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More Than Meets The yeThe Stories ehind the Development ofPlastic Lenses

bout the uthorJoseph Bruneni is the author of LOOKINGBACK, an illustrated history of the AmericanOphthalmic Indusl1} , hard cover book published in 1994 and still in print. He is frequentcontributor to most of the major optical tradepublications and writes regularly-appearingcolunUls in number of them. He serves as special consultant to the Optical LaboratoriesAssociation OLA) and is member of the OcularHeritage Society. He currently serves as an assistant professor teaching ophthalmic optics at theSouthern California College of Optometry.

On the CoverThe cover illustrates key elements in thedevelopment of ophthalmic lenses.Upper rigbt Tltis is the first known painting toshow someone wearing eyeglasses. was paintedin the year 1252.Directly below Pince-nez glasses were in voguearound the turn of the century. They often featured chain or ribbon to catch them when they fell offthe nose. left Frank Strain was one of the two inventivechemists at PPG who developed and patented allyldiglycol carbonate CR-39 monomer) in 1940.Due to the war, ule patent was not issued until 1945.Center model of the atomic structure ofCR-39 monomer. ottom left Tltis energy-efficient landmark glasstower in Pittsburgh, Pa., serves as internationalheadquarters for PPG Industries, global manufacturer of coatings, glass, fiber glass, and industrialand specialty chemicals.

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e ginning

the time World War II began, theplastics revolution was already well underway.Polystyrene resins had been producedconunercially since 1937 and nylon, the firsthigh-performance engineering plastic, was alsoa product of the 1930s. As the war began, boththe Allies and the Axis powers faced severshortages of natural raw materials. The plasticsindustly turned out to be a rich source ofacceptable substitutes. Realization of this factled to concentrated efforts by the industly todevelop other new plastics.

With tlus heightened interest in plastics,PPG Industries-known as Pittsburgh PlateGlass Co. until 1965-began searching for away to create an allyl resin with low-pressurethermosetting properties. Rohm Haas hadah eady developed Plexiglas resin and DuPontchenusts had invented Lucite resin, both ofthem thermoplastic materials. Pittsburgh PlateGlass Co. owned a subsidialy company inBarberton, Ohio, called Columbia SouthernChenucal Company where a research team wasassigned responsibility for investigating clearresins. The term Columbia Resins waschosen to serve as the name of tms proje t.

As a cowpound was isolated and worked onby the team, it was identified by a codenumber. By May 1940, one of the compoundsshowed real pronuse. TIus particular resin wasan allyl diglycol carbonate ADC monomerthat Pittsourgh Plate Glass Co. trademarked

under the rna erial s batch name CR-39. nfuture year ,more than 180 differentcompounds of this clear resin wereindividually researched and investigated.THE TH COMPOUND

The 39th attempt was the most promisingbecause it offered some unique characteristics.Among them was the fact that the resin couldbe combined with multiple layers of cloth,paper and other materials to produceexceptionally strong laminated productscapable of being molded into a variety ofreinforced shapes. Tlus discovelY marked thebeginning of what woul come to be m a j o ~ :new induStly called reinforced plastics.

0The first conunercial use for Pittsburgh

Plate Glass Co. s new monomer iJwolvedcombining the resiJ1 with fiberglass (anotherPitts urgh Plate Glass Co. product) to form a)]molded fuel tank for the B-17 bomber, the ( )famous Army Air Force plane that saw servicein evelY theater of operation during World WarII. The fuel tanks were molded of materialslan1inated with CR-39 resin and lined \\ith aspecial rubber compound that became selfsealing when the tank was pierced by bulletsor shell fragments. ReplaciJ1g conventional fueltanks with tanks lanunated USiJ1g CR-39 resinmade it possible to greatly reduce the plane sweight, extending the bomber s range andcontributing substantially to the war effort.

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... UNITED ST TES P TENT OFFI E

2,370,565

THE SE R H R PE ET IME USES

Avariety of uldustries were contacted in asearch to find customers for the left-overCR-39 resul. Afew individuals in theophthalnuc industry indicated some initialinterest, particularly because of the material sresistance to ullpact. One company wasinterested enough to set up a special researchdepartment to tty to develop plastic eyeglasslenses. The company was Uluvis LensCompany, at that time located Ul Dayton, Ohio.Univis was a leading lens producer illvestulglarge sums in an attempt to produce plasticlenses from CR-39 resin. Their efforts areexplained in greater detail Ul Robert Graham sstOly see page 14). Eventually Uluvisabandoned the project. It s interesting to notethat, following successful production ofplastic lenses by Armorlite, SOL and Essilor,Uluvis did eventually become a major plasticlens producer.

tented Feb. 27 1945

;

did know that when it happened, ulstead of anexpensive railroad tank car, they would end upwith a useless steel-encased slab of plastic.

FUEL MONITORS

THE W R ENDS

Another umovative use for the new CR-39resul in aircraft was production of transparenttubes that were embedded ill fuelliIles runningthrough the flight enguleers compartment,providillg the crew a visible gage to uldicatefuel flow to each engule. These tubes made ofCR-39 resin replaced tubes made of glasswhich were often shattered during combat,spraying gasoliI1e throughout the cockpit.There was also some minor use of transparentCR-39 resm for makiIlg lenses during the warbut the lenses produced were z to thickand prunarily used for reflector andsearchlight applications.

When the war ended Ul 1945, allgovernment contracts were cancelled, andPittsburgh Plate Glass Co s Barberton plantended up with a railroad tank car full of allyldiglycol carbonate CR-39 resin), all thatwas left from wartune production. The 38,000pounds of resin rema.iIung ill the tank carrepresented a costly mvestment for thecompany, so a search was launched for civilianmarkets that could use this transparent resin.PPG old-wners involved durillg that periodremember how tune-sensitive tius projectbecame. CR-39 reSUl rema.iIls a liquid until acatalyst is added. Eventually, however, thematerial polymerizes, or hardens, without acatalyst. In those early days, no one knew howlong that self-curing process would take. They

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anklin Strain, standing at the right,the co-developer of allyl diglycol

C R 3 ~ mOnOlllel alongFrank A1Ils/wt. He is seen here

cussing the ojJticaljJrojJerties of CRmonomer with several PPC

e:recutives. l\1uS/wt ands originaljJatent application,October 15 1940, stated,

we have been able to jJrejJareJlex esters of various polyglycols

as diethylene, trieth lene,jJentaet/l lene,

triprojJylene,dibut) lene, or othercol. Who could have jJredicted

such an exotic chemicalnbination would imjJact C ewear in

~ e a r s to come?

F L T S HE ET M RKET

Until 1960-61 PPG s primaty CR-39 resinsales were for flat sheet applications. Thesesheets of transparent plastic were used forpersonal safety equipment and clothing suchas welding helmets industrial goggles gasmasks etc. Another widespread use of CR-39resin during those post-war years was forwindshields of industrial crane cabs and othervehicles used in industrial plants. Much of theearly work in developing optical lenses wasconcentrated on strong correction lensesprimarily high plus lenses used for postcataract patients. This was an inlportantsegment of the lens industly in those daysbefore development of the inter-ocular lens.

sthe optical industly gradually learnedhow to cast lenses from CR-39 resin and howto edge and surface these new lenses sales tothe optical industly grew slowly but steadilyuntil 1975 when more than 90 percent ofPPG s CR-39 resin sales were to the opticaltrade. In 1975 PPG s marketing expertspredicted that plastic lenses-at that timerepresenting 15 percent of all eyewear in the.S.-would grow to 30 percent by 1978. Few

people outside of PPG believed that optimisticpredictiol i. Today plastic lenses representmore than 80 percent of the S market.

THE T NK R

Looking back to that tank car of CR-39monomer sitting forlornly on a siding inBarberton Ohio in 1946 the PPG employeeswho tried to sell the contents before the resinsolidified uncovered two important facts. Thefirst was that CR-39 monomer was remarkablystable with an amazingly long shelf life. Thesolidifying they feared never came to pass.Their other discovelY was that there wasindeed a viable market for a stabletransparent inlpact-resistant material forproducing spectacle lenses.PP The omp n y

The company known today as PPGIndustries Inc. was founded by two velYdissimilar men. John Pitcairn was aconservative railroad official. In 1880 helinked up with Captain John B Ford aflamboyant entrepreneur. For some reasonnow forgotten these two men came to theconclusion that they could produce andmarket plate glass. This was an ambitiousundertaking because at that point in timeplate glass for the United States was almostentirely imported from Europe. More than adozen U S companies tried to compete in thismarket but all ended as financial failures.Belgium England France and Germanymonopolized both the machinely and the skilledtechnicians required to produce plate glass.

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P ITTS URGH PL TE GL SSOMP NY

With Pitcairn as major stockholder CaptainFord founded the lew York City Plate GlassCompany in 1880 and began building plantin Creighton Pa. didn t take long for the pairto run out of money. To get needed capital thecompany was reincorporated in 1883 as thePittsburgh Plate Glass Co This also marked theyear the company produced their first plateglass. Success soon followed those early effortsand by 1895 the company moved theircorporate headquarters to Pittsburgh Pa. ythis time the company produced 20 millionsquare feet of plate glass annually.

Ford and his sons had disagreement withPitcairn in 1896 and sold their interest inPittsburgh Plate Glass Co They left to foundthe Edward Ford Plate Glass Company inToledo Ohio. In 1930 tllis company mergedwith the Libbey-Owens Sheet Glass Companyforming the well-known Libbey-Owens-FordGlass Company.P ITC IRN T K ES O VE R

With Ford gone Pitcairn took over aspresident and in 1899 established anindependent company called ColumbiaChenlical Company based in Barberton Ollio.TIlis new operation was created to assure PPG

constant supply of soda ash majorcomponent of glass. The Columbia ChenlicalCompany was responsible for inventingCR-39 resin during World War II. J.n 1951Pittsburgh Plate Glass Co became the soleowner of Southern Alkali and merged it withColumbia forming the Columbia-SouthernChemical Corporation. Tllis companyultimately became PPG s chenlical division.

y1900 Pittsburgh Plate Glass Co wasselling 13 million square feet of plate glassannually. The company had become thecountty s most successful producer of plateglass. Imported plate glass dropped to lessthan 15 percent of what the nation consumed.That year PPG bought majority interest inPatton Paint Company which became PPG scoatings resins division. In 1902 thecompany reversed tradition and expandedoperations to Europe by buying glass factoryin Courcelles right in the heart of the Belgianglass industty

PP fOllnderJolm Pitcairn

founder aptainJohn

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TO Y

PPG Industries, Inc. is a diversified globalmanufacturer and a leading supplier ofproducts for manufacturing, construction,automotive, chemical processing andnumerous other world industries. Thecompany produces protective and decorativecoatings, flat and fabricated glass products,continuous-strand fiber glass, and industrialand specialty chemicals. They operate 70major manufacturing facilities in Australia,Canada, China, England, France, Germany,Ireland, Italy, Mexico, the etherlands,Portugal, Spain, Taiwan and the United States.The company conducts research anddevelopment at eight facilities worldwide.h e v o l u ~ i o n o f

p h ~ h a l r n i c ensesThe word lens comes from the Latin word

lentil, a species of bean that rather vaguelyresembles the shape of a lens. Single pieces ofconvex-shaped glass or rock crystal have beenfound in ruins dating back thousands of years.These primitive lenses were used as magnifiersbut wasn't until the 13th century that anyonethought of combining them into spectacles.

RE ING S TONE S

The first mention of magnifying lenses isfound in a famous treatise on optics written byArab physicist, al-Hazen (996-1038). AI-Hazenobserved that a segment of a glass sphere, ineffect a plano-convex lens, would magnifyinlages. Later, Italians would call magnifyinglenses lapides ad legendum which translates tostones for reading, most likely because theywere made from rock crystal rather than glass.

The very earliest spectacle lenses weremade of quartz crystal and were given thename pebble lenses in the optical trade.Other early lenses were created from handblown glass. As the optical industry grew,hand-blown glass was gradually replaced bymore easily-formed lens blanks made from flatsheets of glass. These were called droppedlenses because of the process in which flatsheets of glass were heated until they softenedenough to drop into cavities that shaped theblanks to a rough curve.

The earliest origin of eyeglasses is a matterof some dispute. In his famous Opus majus,Roger Bacon described how a convex lensmagnified and offered a suggestion that such alens might help those with vision problems.\Vhile Bacon did not invent glasses, is stronglybelieved that their first use undoubtedly startedduring his time 214-1294).

JeT) BU Q)rillcn r r nb (jC~ u f f m a n c f } c r r l ~ r t f g c r i c f 2 t lC;:Oon tliCT Jig bip auff acf,Oig ;arl1marmit baG9ficf)fin ~ u t t t l a r t 1 1::Dit g ~ t u f i \lonltllcr olltr 5 or

~ r t l > n llit glMtr '))0 m nnlllvorttl~ a t l u r c ~ mil frcf}t/gar ~ d l l 1 t 1 l l rcf2ilrff

This Middle AgesWOOdCllt shows acllstomer trying one eglasse from astreet merchantWOOdCllt, Werke GRodenstoch

~ I I l l n c h e n .

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E RLY LENSES

Contemporaly writers tell us that the Rom anEmperor ero viewed sporting events in hiscoliseum through an emerald lens. Theemerald was probably chosen because of itspleasing green color. Tllis was undoubtedly theworld s first tinted sun lens. It s also believedthat the stone cutter accidentally produced slight concave shape to the stone wllich mayhave helped near-sighted ero see better.RYST L LENSES

The earliest spectacles were produced byglaziers in Venice Italy. Lenses in these firsteyeglasses were made from quartz or rockClystal and produced by gold craftsmenexperienced in working with rock Clystal whenproducing jewelty. Artisans at that time wereclosely governed by individual statutes thatapplied to evelyone engaged in specific craft.The Cristallieri as these craftsmen came to becalled received their own code in the fall ofthe year 1284. Tllis seems to indicate thatspectacles must have been common by tIlisperiod they required their own regulations.

One of the regulations governing spectaclemakers involved substituting rock Clystallenses with inferior glass lenses. Tllis wasstrictly forbidden. Rock Clystal was velYexpensive wIllie glass was considered lessdesirable material for lenses. Early artisanswere pernlitted to make lenses out of glass butonly they promised they wouldn t clain1 them

to be quartz. On]une 5 1301 the city ofVenice changed the rules and pernlittedpersons to make reading spectacles fromglass providing they first took an oa in frontof judges that they would never represent thelenses to be rock Clystal.

Bishop Ugone da Provenza, shown in this th centu1)jJainting s thefirst historicalfiguTe known to wear glasses.The jJainting can still be seen in the chw ch oj St. Nicolo inTreviso near Venice His glasses aTe simjJle magnifiers withshort handles, riveted together so they could jJerch on his nose.Painting copy Werke Rodenstock, Nlunchen.

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THE F IR ST EV ID ENCE EYEGL SSES

The earliest historical figure documentedwho wore glasses was Bishop Ugone daProvenza. This Dominican priest was portrayedin a painting by Tomaso da Modena in the year1252. The painting can still be seen in thechurch of St Nicolo in Treviso, a city nearVenice. His glasses were really nothing morethan simple magnifying lenses with shorthandles, riveted together so they could perchon his nose (see illustration).GL SSES NDTHE PR IN T IN G PRESS

Spectacles did not come into conunon useuntil some time after Guttenberg invented theprinting press during the mid-1500s. Thatevent marked the real begiIming of the need tocorrect vision with eyeglasses. Lenses usedduring that period were biconvex in form andused primarily to correct presbyopia. Sometime later, it was found that biconcave lenseswould help nearsighted persons see moreclearly in the distance. It wasn t until 1500 thatlenses were graded by their focal power. Thiswas the idea of a man named ]ohaImes Kepler.Prior to Kepler, lens powers were efil e bythe age of the person wearing them.

By the time the 19th century began, mostglasses were sold in hardware stores:Gradually, gold and silver were used is frame

materials, aIld jewelers bec e logicalsuccessors to hardware mercH allselling glasses purchased them as r ad -madeglasses, usually one dozen to the box, aIld soldthem under an inch-number system. wayfrom large cities, itinerant eyeglass peddlerswere the primary method of eyeglassdistribution. Most of their wares wereproduced by EuropeaIl sources. People whothought they needed glasses would tryonready-made glasses, one after another, untilthey found a pair that helped. The lenses inthese factOly-made glasses were always theSaIne power for each eye.LENSES

Bausch Lomb aIld American Optical werethe first AmericaIl compaIlies to iIlitiate massproduction of glass spectacle lenses. Prior tothat time, most lenses were imported fromEurope, either as rough blanks or in uncutform. No optical glass was maIlUfactured in theUllited States until World War cut offtraditional import glass sources for tIlis countly.P E L E L EN SE S

Lenses made of rock crystal were origillallyintroduced in England under the name ofScotch Pebble and later as Brazilian Pebble,naInes indicating their country of origin.Crystals are found all over the world, but thoselarge enough to make into eyeglass lenses are

During the eighteenthcentury when wigswere cOJJwwnly wornby IJerso17s substance eyegLassFames Jea tu red specialsl)[lhlLa tYIJe tempLesthat wOllldJit underthe wig, as seen here.During this period,many len es were made nattlral roc/ cI lstal jJebble). The stoneswere onlyJound insmall sizes andolJticians ofteninserted the Lenses icircuLar shells made leat/leI; hom or woodso the Fames could beLa gel; as seen here.

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only found in a few countries. During theperiod when pebble lenses were popular,spectacle lenses were about the size of a halfdollar coin. The best crystals were found inBrazil, and interestingly, no rock crystals inpaying quantities were ever found in the UnitedStates. Pebble lenses normally costconsiderably more than glass lenses. Theywere much harder than glass and, as aconsequence, much more difficult to grind andpolish. Their harder surface made them lastlonger without accumulating scratches. Tlliswas highly valued by consumers.

Even when glass lenses becanle plentiful,pebble lenses continued to be sold as superiorlenses because of their longer wearingqualities. It wasn t uncommon for eyeglasses tobe passed on from one generation to another.The cost for pebble lenses kept rising as thesupply of rock crystal dinlinished, but theywere still being sold well into the 1920s.FL T L NS S

Early lenses, whether made of pebble orglass, were all made in flat form, or biconvexfor plus powerslbiconcave for minus. Flatlenses were easier to manufacture, and no onethought to mal e dIem any other way Flat lenseswere still widely used into the 20th century.

The next evolution in lens form came aboutwhen lens designers tried to elinlinate visualproblems created with flat optics use. Lens

makers found dlat lenses ground with aconcave curve on the back side and convex onthe front surface were positioned further fromthe eye and, as a consequence, would provide

a considerably wider field of view Tills had theadditional benefit of reducing contact betweenthe lens and the wearer s eyelashes, sometllingthat had always been a problem with flatlenses. Meniscus lenses were described asearly as 1645 but not used for eyeglasses untilthe periscopic lens was introduced in 1804.These lenses had a standard -1.25 back curvefor all powers. Conventional six base melliscuslenses first became available around 1890.L N S T IN TS

Early in the evolution of ophthalnlic lenses,lens producers looked for ways to increaseprofits, for them and for their retailers. Thefirst lens add-on was simply adding color toraw glass. Some of the early uses of color inlenses included treatment of disease and evenclaimed improvement of vision. Early in the19th century, blue, pink and green lenses wereintroduced. Later, Dr. William Crookes, anerninent British scientist, developed a specialcolor that filtered infra-red rays and wasnamed Crookes after the inventor. This coolblue/gray shade was quite effective butunfortunately gave wearers a rather ghastlylook, with unattractive shadows beneath theeyes. American Optical produced a moreattractive pink shade called Cruxite. Betweenthe two World Wars, pink lenses became very

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popular. Soft-Lite lenses by Bausch Lombultimately became the top-selling premiumlens. Later BM developed Ray-Ban andG-1S proprietaly sunglass lenses. Ray-Ban istoday on the ten best-known trademal'ksin the world.

listed +0.50 +0.50 compound correctedcurve uncut lens at 1.80 per pair. The samelens in toric form (non-corrected curve) was1.55 pair. The difference was only 25 cents,but t was more than thirty years before oldfashioned toric lenses were totally eliminated.

This was also time when labs first startedusing automatic bevel edgers for finishinglenses. One of the major benefits of beveledgers was the ability to apply special 'hidea-bevel to high minus lenses. This is anautomatic way of applying most of the bevel tothe back side of the lens, hiding the lensthickness behind the frame. Plus cylinders,especially in higher cylinders, produced anunattractive bulge in the front rim of theframe, follmving the mds of the cylinder. When

s fused multifocals gradually took over themultifocal mal'ket, replacing old-fashionedone-piece lenses like the ltex, new problemarose. Fused multifocals were surfaced on theback side which meant labs surfaced themwith the cylinder on the back surface. Singlevision stock lenses at that time were allproduced with plus cylinders on the front side.s patients aged and went from single visionlenses to bifocals, they often experienceddifficulty adjusting to visual differences createdin switching from plus cylinders to minuscylinders.

The tough job then became convincingeyecal'e pofessionals to prescribe correctedcurve lenses rather than the less desirabletoric lenses. o provide an idea of thedifference in cost between toric and correctedcurve lenses, American Optical's 1935 prices

This led to the development of correctedcurve lenses. These modern lenses changedbase curves for evelY one to two diopters of

ower. Before long evelY lensmanufacturer was producing st nd rd aselenses, called toric len ong with separate line of corrected curve lenses.

Lens designers found that changing lensdesign from biconvex or biconcave to 6.00diopter curve provided wider field of viewfor the wearer. They also found other inherentoptical distortions that cropped up as eyeglasslenses grew larger with increasing frame size. was determined that changing front curvesas lens powers changed would minimizemarginal distortions, producing better acuityfor the weal'er.

e use oj colored glass lensesJor impliedrapeutic pmjloses or simplyJor the visu l

mJort they provided was the firstncementJor ophthalmic len es One ojmost exciting asjlects oj lenses made from

resin was their ability to be tinted toy color oj the rainbow n imjlossibilith glass lenses. Best oj all the tinting

be done in a retail oJfice oJJering n wfit ojlportllnitiesJor evel}one.

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cylinders are ground on the back side of thelens, tltis cylinder bulge is completely hiddenby the frame. Tltis provides a considerablecosmetic advantage for minus cylinders, inaddition to their visual advantages.

Minus cylinder lenses were more expensiveto produce than plus, but their advantageswere too obvious to ignore. Lensmanufacturers, facing the heavy costs ofconverting production equipment to minuscylinders decided to convert their lenses tocorrected curve form at the same time. Thisconversion to single vision minus cylinderstock lenses effectively doomed toric lenses, toeveryone s great relief. Today, all single visionlenses are produced in minus cylinder formand are also considered corrected curve.PL STI LENSES

great deal of work was done in Englandbefore and during World War in an effort todevelop a lightweight, shatter-proof plasticlens. Most of tltis work resulted from theBritish experience working with acrylic polymethyl-methacrylate), a material widelyused in Great Britain before and during thewar for aircraft windsltields. IGard, a divisionof Combined Optical Industries, Ltd., aprominent British lens manufacturer, beganproducing prescription lenses made of acrylic

These enjoyed modest distribution in theUnited States before World War II. After thewar, McLeod Optical of Providence, R.I., begandistributing inlported acrylic lenses tb otherlabs located in the United States. These IGardlenses were produced only in finished uncutform and could not be surfaced. They werelightweight but proved to be brittle, subject toscratching and prone to yellowing after a fewmonths in inventOly.

There were other attempts to utilizeacrylic materials but the plastic lensrevolution was virtually dormant untilPittsburgh Plate Glass Co. came up withCR-39 resin. That event eventually madelightweight plastic lenses a reality.

uring the scramble to findjleacetime uses for CR-YfFJresin some innovative PPscientists projlosed thatcolorful long-lasting fishinlures could madefrom tmaterial. Fortunatel wiseheads concluded thatojlhl/wlmic lenses offeredgreater opjlortunities.

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h e u e s ~ fo r l a s ~ i c ensesP RT ON

s the country came out from the depths ofthe depression, popular magazines of the daywere filled with stories of the wonders of newplastic materials that promised to create whole new world for consumers. Housewivesbegan discovering the benefits of sturdy,lightweight housewares made from Bakelitesynthetic resin, the convenience of cellophanefood wrappings and the ease of self-stickScotch tape. The 1939 World's Fair in ewYork carried the theme World of Tomorrow,and much of the world they predicted involvedthe benefits and glories of plastics.

One familiar plastic developed during thethirties was polymerized methyl methacrylate(PMMA), introduced in 1937 as Lucite andPlexiglas resins. This material had excellentoptical properties and was considered suitablefor eyeglass and camera lenses, and forproducing special effects in highway andadvertising illumination. Another plastic waspolytetrafluoroethylene, first made in 1938 andeventually produced conunercially as Teflonresin in 1950. Also e v e l o p ~ during the1930s was the synthesis of nylon.

There were few far-sighted people in theoptical industry who were convinced that oneof these exciting man-made materials wouldeventually prove to be suitable material for

ophthalmic lenses. 1\vo basic factors motivatedthis desire for plastic lens. One was the safetyissue (greater resistance to impact). The otherwas comfort (lighter weight lenses).S F TY ISSU S

Auto manufacturers faced similar safetyissue with automobile windshields. The autodriving public grew concerned over theserious cuts and injuries that were theinevitable result of broken car windows, oftenin the most minor of traffic accidents. cleverglass maker found that lan1inating d in sheetsof plate glass over strong inner layer ofplastic minimized injuries from broken glass.The first lan1inated automobile windshieldshad an interlayer of cellulose acetate.Pittsburgh Plate Glass Co. produced superiorwindshield with polyvinyl butyral interlayerwhich was more yielding, and therefore safer,than cellulose acetate. When laminatedwindshields broke, shards of glass were heldtogether by the plastic core. Laminated glasswindshields worked so well that someone inthe optical industly decided to adapt similarlaminated process to ophthalmic lenses.

Called Motex, these safer laminated lenseswere moderately successful during the thirtiesand forties. They were widely advertised as non-shatterable lens and used mostly forchildren's eyewear. Each pair of lenses camewith 15,000 insurance policy against eye

m g e ~ Since there were two layers of glass ineach lens, the layers were kept thin in an effort

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The famous railroad tanl{carjilled with 38jJounds of CR-39J9 monomerthat prompted the search forcivilian uses for all) l digl colcarbonate ADC) can be seenin this 945plwtograjJh ofthe shijJjJing ,ard at PPC sBarberton, Ohio, plant.These marketing efforts led tothe successful develojJment oflightweight jJlasticojJhtlwlmic lenses.

In spite of these disappointments, many in theindustry were fascinated by the crystal clearproperties of PMM and continued struggling tomake ophthalmic lenses from the material.Ironically, PMM would later prove to be the idealmaterial to use in fashioning corneal contact lenses prior to the development of soft contacts).WORLDW IDE DEVELOPMENT OFPL STI LENSES

Development of what led to today s plastic lensescame primarily from the efforts of threemanufacturers. The earliest pioneer was RobertGraham, first with the Dnivis Lens Company andlater with ArmorLite, the company he founded inCalifornia. For a period of s x years, Graham wasthe only source for plastic lenses made of CR-39resin. Later, SO in Australia began experinlentsfor producing plastic lenses, and during that sametime franle, Essilor in France began working toproduce a lightweight organic lens.

The story of how each of these innovativecompanies solved the problems of producingplastic ophthalmic lenses follows

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Robert Klar/l GrahamJounded theAnllorlite Com/Jan in Pasadena Calif.For a period oj six years he n hiscompany were the world s only sourceJorlenses made oj m l eJ:

T L

Tlus was a bitter pill for Graham. Hebelieved UIuvis was giving up too easily. Thetecl1Jucians who had been working withGraham on the plastic lens project felt thesame way When luvis shut down the project,these tecl1Jucians lost their jobs. Bob Lanmanhad been involved with casting lens researchand anti-reflection coating technology at Uluvisand was one of the ones who was let go.Grahanl suggested he and Lanman set up a labof their own to work on the plastic lensproject. Both men moved their fan1ilies fromDayton, Oluo, to Califonua, taking all but oneof the Uluvis lens researchers with them. Theyset up their new company in Pasadena.Graham and Lanman agreed to each draw asalary equivalent to what they had earned at

luvis. Whenever there were no dollars to paythem, they would take the equivalent in shares.Initially the new company was called PlasticLens Company, but the name was later changedto Armorlite.

The terms of their agreement also pernuttedGralulill to fit contact lenses on the side whenthere was no money for salaries. For severalyears, the Graham family was supportedprimarilYl,by contact lens fees Grallam was aconsultant to Kevin Tuohy, inventor of plasticcorneal lenses) Grallam s accumulated stockownerslup and Ius cash investment evennlallymade him Armorlite s largest stockholder.

The first plastic lenses produced by theArmorlite Lens Company were made ofpolymethyl-methacrylate PMMA) a materialbetter known by the trade names Lucite andPlexiglas resins. Injection-molding of PMMlenses had also been tried but was neversatisfactOlY because of striae introduced duringthe injection process. The required metalmolds were expensive and had a short life.

Graham s team developed a differentprocess wluch involved machining discs madeof PMM to the approximate desired curves ona lathe. These turned blanks were polished bypressing them between lughly polished glassmolds, using moderate heat and pressure. Tlusminimum-flow process produced a finelooking lens that was optically clear with nomachining grooves or residue marks.

nfornmately, the lenses enjoyed onlymoderate success. The company had earliertried malting lenses out of styrene butabandoned that material because it was too softand prone to scratclling. The new PMM lenseshad the sanle problem. Excessive scratcllinghad become the insurmountable problem.

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C R 9 RESIN

For some time Dr. Graham had knownabout CR-39 resin, the allyl resin initiallydeveloped by PPG as bonding solution forwar planes. CR-39 resin had first been usedduring World War II for fuel tanks in bombers.Sheets of tItis new plastic had also beensandwiched between thin pieces of glass andused for bomber windows, strengthening theglass sheets and, in effect, reducing theirweight. Tltis lowering of gross weight extendedthe bombers' flight range. CR-39 resin hadbeen classified as militat)' property duringthe war and, as consequence, \\asunavailable to Ultivis. Graham (still at nivis)managed during the war to gain access to fivegallons wltich he used for experimentalpurposes. With the war at an end, andPittsburgh Plate Glass Co sitting with railroad tank car full of the material, word ofits availability reaclIed Pasadena whereGraham jumped at the opportllltity to tl)' itonce again for ophthalmic lenses.

Uke PMMA CR-39 resin was optically clearbut turned out to be tItirty times moreabrasion-resistant than Plexiglas or Luciteresin. There were, however, certain inherentproblems in casting lenses with CR-39 resin.The first one is easy to understand. Theoriginal design function of CR-39 resin was toact as bonding agent for gluing togetherlaminated multi-ply materials. This proved tobe less than desired property for lens

casting because the resin tended to bond tothe mold, particularly when the mold wasmade of metal. Fortllllately, Graham's groupfavored glass molds.S HR I NKAG E

An equally serious problem was that lensescast from CR-39 monomer experienced 14percent shrinkage as the material cured. Tltiswasn't problem when casting plano lenses,since the shrinkage merely made the lensedges retract slightly. When lenses were castwith corrective power, however, variance intItickness between the center and the edge wascreated. Tltis resulted in differentialslu'inkage wltich inevitably created opticaldistortions in the finished lens. Grallam'sanswer to tltis innate property of CR-39 resinwas to cast tItick blanks in wltich the backcurve matched the finished front curve. Tltisform allowed uniform shrinkage during curingwith no induced distortion. Armorlite wouldthen grind and polish the back surface to therequired curve and tItickness.

Graham would later write about thosetraumatic days. We will never forget thosenights, month after month, when we sat by theovens listening to the sound of cracking glassmolds Breaking of glass molds resulted fromthe combined action of the resin's sluinkingfactor (14 percent) and its adhesive properties(sticking to the mold). Eventllally, after greatdeal of trial and error, Graham's persistence

J\ Iost of those involved incasting lenses madefromCR-39J9 monomer duringthe first several years werefully convinced that no onewould be able to cast bifocalsin this new lightweightresin. As a result, everyoneconcentrated on singlevision blanh Here, aflortion of the da) sproduction is seen on it sWO l to jloc wging.

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TR IP TO P ITTSBURGH

During this period, PPG invited Graham tovisit the Pittsburgh office in appreciation forhelping them find major peacetinle use forCR-39 resin. Dr. Dial, one of the originalpatent-holders of CR-39 resin, hosted luncheon at Pittsburgh's Duquesne Club. Therewere many flattering speeches about Graham singenuity, accompanied by awards andsouvenirs. When Graham left the dining roomafter lunch, he found bright red carpetstretching down the hall and down the steps tothe curb where long black limousine waited.Dr. Graham tells the story himself in Iusautobiography, RK.G.

For sLx years, Armorlite had worldmonopoly on lenses with CR-39 resin. Thisexclusivity e ed when Essilor, then SOLAfollowed by American Optical, beganproducing hard re in lenses made ofCR-39monomer. Dr. Graham poifits out todaywhen American Optical introduced their ownplastic lenses, Annorlite s business doubled.Plastic ~ n s s had come of age

I thought, ow, these PPG men reallyknow how to make fellow feel ood. I hadn'tgone far on the red et before militaryofficers hustled me off into side vestibule.

1 adjoining room, meeting s being held tfi e on ockefeller, vice president of theUnited States. Jus for little while there, Ienjoyed his red carpet. ~ : :

paid offwhen his team found better glass formaking molds and was able to add releaseagent to the monomer. Finally, they successfullycasted lenses with CR-39 resin.

The year 1947 saw the Armorlite Companyincorporated and the beginning of lensesproduced with CR-39 resin. For the next sLxears Graham's company was the worldwidesou ce for hard resin lenses. During thisp riod, Armorlite was forced to act as bothmanufacturer and lab processor. ab duringthat period were neither trained nor equippedto pro s plastic lenses, so the only availapleprescriptions were those that fell withinArmorlite's stock lens range. To produc nonstock corrections, r\rmorlite was the Illysource for surfaced plastic lenses. Eventually,

am had to face decision. Was Armorliteto ea 'ocessing laboratory or manufacturer? The company had to decidewhere the' skills re of t value.Grah cho manufacturing, bettiIi that withplastic lenses now reality, processing labs forRlastic lenses would spring up. Armorliteclosed their laboratory and, from tha p6ll1ton, devoted the plant solely to manufacturinglenses with CR-39 resin.

T HE S T R T U P

M E L N I

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S R T HES

The only down side in comparing plasticlenses to glass was plastic s susceptibility toscratching. Armorlite s scientists triedeverything to improve scratch resistance,reviewing more than 2,000 patent abstracts intheir quest for suitable abrasion-resistanttreatment. The basic problem was thedifference in thermal-coefficient of expansionbetween coatings and lenses made withCR-39 resin. This usually resulted in crazedsurfaces after exposure to temperaturevariations.

In the early 1970s, the famous MinnesotaMining and Manufacturing company (3M)came to the conclusion that they had theanswer. Coatings had always been one of 3M stechnological strengths, but finding the rightcoating for lenses made from CR-39 resin waseluding even these innovative scientists. Amongtheir researchers discoveries was that thecleanliness requirements for productioncoating of ophthalmic lenses exceededanything the company had previouslyexperienced. The ultimate answer to thecleanliness problem turned out to be production facility that reduced airborneparticles to minimum

From 1974 to 1976, 3M refined theircoating process. They set up special testlaboratories to evaluate treated lenses. Lensesthat looked fine to the 3M chemists w ~ r l non the project were totally unacceptable to labtechnicians who had better understanding ofwhat was required. Eventually 3M offered thecoating service they developed to labs in fivestates on test market basis.

More than 25,000 pairs of hard resin lenseswith the new 3M treatment were sold in thetest market from April 1978 to December1979. t the end of the 20 month test, 3Mfound that all the test labs wanted to continueselling the coated lenses. Just prior to tltistime, 3M, concluding they had real handleon the optical business, bought the ArmorliteCompany and transferred the scratch-coatingteclmology to Armorlite. The 3M coatingteclmology was introduced nationally underthe trade nanle R X Plus.

When Armorlite was sold to 3M, theoriginal investors who had paid 1.00 pershare for their stock received 4,164.88 pershare under the terms of the sales agreement.

inal insj ection sellfinished blan

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S IGNET UPTOW

Signet ptown was an all-plastic wholesalelaboratory rarity at the time the companywas formed. They also casted lens blanks andsoon becanle major lens manufacturer. By1971 they produced single vision bifocal andtrifocal lenses as well as an innovative newpost-cataract lens design called hyperaspheric.

In 1976 the company was sold to AmericanHospital Supply Corporation who sent RichardOrmsby to serve as general manager. In 1981Ormsby along with Robert Jepson purchasedSignet from American Hospital SupplyCorporation. Later that sanle year Ormsby andJepson also purchased Armorlite from the 3MCorporation. The two companies were mergedto form Signet Armorlite Inc. From that pointon the company was an affiliate ofJepsonCOl1JOration. Signet Annorlite was laterpurchased from Jepson by the Eagle Corporation.In 1993 Signet Armorlite formed jointalliance with lndustrie Ottiche Europee. Eachcompany continues to operate independently.SOL OPTI L

Today SOLA Optical is recognized as one ofthe w o r ~ s major manufacturers of spectaclelenses but the company evolved from humblebegimtings. The first experiments of castinglenses made of CR-39 resin in Australiabegan in 1956. The company founders were

group of men led by oel Roscrow whoworked for prominent optometric practicenamed Laubman Pank in the City ofAdelaide. Roscrow and his associates begantheir efforts in garage by using gas ring and saucepan experimenting in an effort toproduce plastic lenses. Hard resin lenses werejust beginning to make inroads in othercountries prinlarily the United States andFrance. Tltis small group of Australianentrepreneurs was determined to cast lenses intItis new CR-39 material.

By 1960 Noel Roscrow convinced theowners of the optometric practice to let himspin off his small group and form newcompany they would call Scientific OpticalLaboratories of Australia the company nowknown as SOLA As means of producingcash flow during those early years theemployees also performed number of othertasks. They did binocular repairs for theAustralian army vacuum coated ophthalnticlenses made optical instruments andsomewhat incidentally manufactured all rearvision mirrors used for cars produced inAustralia. Whenever they could steal some timeaway from these tasks they worked on castinglenses with CR-39 resin. They established branch in Melbourne in 1965 formanufacturing and repairing instruments butlater converted that plant for the purpose ofprescription surfacing and glass mold-making.

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PLANO LENSES M ARKET ING LENSES WITHC R 9 RES IN

Initially the company concentrated oncasting to prescription completely finishedlenses. They found surfacing and polishjnglenses made with CR-39 monomer difficultnot impossible so casting finished lensesseemed to be the ay to go. Gaskets forseparating the molds were made by hand andthe lens molds were hand filled individually bysyringe. It was a very slow process. eedinganother product the company began massproducing plano lenses for sunglass andindustrial use. Manufacturing lenses withCR-39 resin was still a new process andRoscrow and hjs team had no one to tell themhow to do it.

SOL concentrated on plano lenses for h\oreasons. First pIanos were easier tomanufacture and the owners believedproducing pIanos would provide training tohelp their people solve the greater problems ofcasting prescription-power lenses. tthat timethe common opinion of most casters was thatmanufacturing senti-finished blanks \\ as 10times more difficult than pIanos and makingfinished prescription lenses 10 times moredifficult than senti-finjshed. The secondreason and perhaps more important reasonfor producing pIanos was their belief thatbroad distribution of plano plastic lenses bSOL would help convert the world to thebenefits of these new lighh\ eight lenses.

To establish plastic lenses as a v i ~ lalternative to glass SOL first had to convincethe eyecare professionals in Australia. One ofthe early marketing promotions the companyimplemented \\ as making thousands of clip-onsunglasses with plano lenses and bundlingthem into batches of five These bundles eresltipped out to hundreds of opticians andoptometrists throughout Australia. One pair wasfree and the other four were billed at a speciallow price. Seventy percent of the retailersreceiving these bundles kept and paid for thesunglasses 15 percent kept them and didn tpay and five percent wrote to SOL to say howimpressed they were with the company spositive attitude regarding plastic lenses. Thebalance complained bitterly about the use ofsuch cheeky sales tactics. The end result ofcourse was a steadily growing acceptance oflenses with CR-39 resin in Australia.W O RL D P RO DU CT IO

tthis time there were only threecompmties worldwide making any seriousattempt to manufacture plastic lenses. Thesewere Essilor in France Armorlite in the nitedStates and SOL in Australia. For reasons thatno one has ever determjned each companycarved out their own niche in concentratingproduction efforts. Essilor s efforts were aimedat producing firtished lenses Armorlite

Casting lenses from CR-3gJ9 resinrequires meticulous cleaning andcareJor the jJrecise glass molds inwhich they are cast. JVIclll) stejJs inthe jJrocess are accomjJlished in aclean room environment In thisjJhotograjJh, trays finished stocklenses are removed Jrom the ovenJollowing curing the lenscoating

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concentrated on semi-finished blanks andSOIA zeroed in on plano lenses.len SOIA began manufacturing senli

finished lenses with CR-39 resin they founda new problem. Due to the material sshrinkage when casted the lens curveschange. n the early days calculating thecurves that each mold should have to acllievethe desired front curve was an extremelydifficult task. Seven-figure logaritlmls wererequired for the calculations. One of Laubman Pank s people was a rna ematician who aspersuaded to join Roscrow s group at SOIA.He was to spend tlle rest of his life calculatingcurves or tlle company s Igrowing asso tmentof lenses.

SO soon realized that as big as Australiawas the Australian market could not supportme kind of manufacturing plant meyenvisioned for themselves. sa result tlleyfocused on export sales. In 1968 a foreignoperation was opened in Japan expanding inthe early 1970s to the luted Kingdom ItalyBrazil and finally the United States in 1975. Bytlus time SOIA had evolved into a globalnetwork of companies. Their senli-finished

line was manufactured with a 68 mmdiameter at that time the largest availableblanks in the world.

O P NIN G T H U M RK T

When SOIA came to the Uluted States theyopened a 15 000 square foot facility inSllI1Jlyvale Calif. tthis time the U S lensmarket was still donlinated by glass lensesrepresenting 70 percent of the market at thetime SOIA s American plant opened. saresult the company s marketing efforts duringthe 70s were devoted to aggressivelyconverting the market to lighter more impactresistant lenses. Growing rapidly the companymoved their S manufaculring operations toa much larger facility in Petaluma Calif. andbroadened the product line. nadditionalproduction site was set up in Mexico in themid-1980s.

One of the main linutations in SOIA sgrowth was the lead time for expanding andmaintaining the wide range of precision moldsrequired for casting. In 1975 a specialistcenter was established in Singapore to supplyglass molds to plants in Italy Brazil the nitedStates and Australia.

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P ILK IN GTO GROUP

In 1979, SOLA was acquired by thePilkington Group of the United Kingdom. Oneof the reasons for SOLA s remarkable growthwas the U.S. market s shift from glass to plasticlenses. By 1983, the U.S. market was over 50percent plastic and by 1992, more than 80percent. SOLA took evelY advantage of tilisgrowing market.

In 1987, SOLA s parent company, Pilkington,acquired the vision care business owned byRevlon, including Coburn Optical. The formerRevlon operations were operated separatelyfrom SOLA. One exception was the Coburnglass lens business wllich was added to SOLA sorganjzation.N W OWN RS

In 1993 the SOLA Group was purchased byAEA Investors, Inc. Tilis privately-heldcompany, founded in 1968 as AmericanEuropean Associates, Inc., invests insuccessful, industly-Ieading compallies forlong term growth.

Today, SOLA s operations span the globe,operating 12 manufacturing sites on fivecontinents with sales offices in 16 countries.EvelY week, SOLA customers, located in some70 nations, order more than one millionlenses. The company estimates that more than

one hundred million people around the worldare wearing SOLA lenses today. Even thoseoptimistic dreamers in Adelaide couldn t haveforeseen what w ~ u result from those primitiveattempts to make plastic lenses in garage.

ss i lor In t ernat ional

To understand Essilor s role in thedevelopment of plastic lenses, it s necessalY toreview the origins of what has become thelargest optical company in the world.SSILOR F MILY TR

The Lissac Company was founded in 1931by George Lissac, an entrepreneur whointroduced marketing to the conservativeEuropean optical industry. Lissac later createdSlL (Societe Industrielle de Lunetterie) in1946 and separate company, LOS (LentillesOphtalnliques Speciales), in 1948. These twocompanies included frame and lens researchand development, manufacturing anddistribution operations. SIL the frame division,created the revolutionaLy AMOR rimless framein 1949. AMOR is condensed version ofthe French word amortisseur wllich meansshock absorbing.

Rene Grandperret, with LOS developed anearly interest in plastic lenses, dating back tothe late 1940 s. In 1952, LOS introduced the

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ORMA 500 lens made from Plexiglas resin,marking the beginning of plastic spectaclelenses in France. Lenses made from Plexiglasresin were only marginally successful becauseof the familiar problem of scratching. LOSeventually found what they decided was theideal resin in the United States and beganexperimenting with PPG s CR-39 monomer.

After years of continuing research, LOSeventually mastered the difficulties of castinglenses from CR-39 monomer and introducedthe ORMA 1000 lens with CR-39 resin in1956. This lens was patented and introducedworldwide in 1959. The following year, thename of the lens division was changed fromLOS to LOR (Lentilles OphtalmiquesRationnelles). By 1961, SIL had introduced thepolymil frame. In 1966, the Lissac groupmerged with Telegic, a company specializing inthe production of corrective lenses. Then in1969, Lor-Telegic joined the other division ofthe Lissac group, SIL (Society Industrial deLunettegy) to form a French company with thenow familiar name of Silor. ORMA 1000 lensesmade with CR-39 resin were introduced in theUnited States by Silor s American subsidiaty, LaLunette de Paris.ESSEL

Meanwhile, another significant Frenchcompany, Essel, began to use the company sname in marketing ylor frames, an

inlproved version of the AMORframe created by Lissac in 1955 andVarilux optical lenses, introduced in1959. Essel was formed in 1848 inFrance during the Spirit of LaborCooperation, the revolutionary sociopoliticalworker s cooperative. In 1955, Essel createdthe ylor frame which enjoyed huge success.The cash flow generated by ylor frameshelped finance the r i l m ~ optical lens.

The marriage of these two companies(Silor and Esse}) brought together recognizedophthalmic brand names ylor, AMORVarilux and ORMA 1000), research anddevelopment teams, and major manufacturingand distribution networks. The two mostimportant optical companies in France mergedto become Essilor International.PL STI LENSES

The company s first successful correctivelenses were cast on April 29, 1954 by BernardMignen when he successfully polymerizedlenses with CR-39 resin in glass molds. Hisexperiments took place in the kitchen of afactOly in St Maur, France, which had beenrecently purchased by Georges Lissac. Earlyefforts were unproductive, primarily becauseof problems with breakage of the glass moldsand great difficulty in separating lenses fromtheir glass molds. Eventually, in 1959, thecompany successfully launched commercial

The introduction lightweight lenses madefrom resin had amajor imjJact on eyeglassframe Jashions s the lensegrew in jJoplilarity, so didthe size frames and beforelong, stylish oversizef ) egla ses became the leaderin f ) ewearJashions. ttractivef ) ewear like thatworn b) the model wouldhave been imjJossible withglass lense

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production of lenses made with CR-39 resinunder the trade name ORMA 1000. Thatbecame possible when Jean Boudet andBernard Mignen developed an improvedmolding process.E A RL Y A TT EM PT S

In 1941, Rene Grandperret, 20 years oldand a new employee at Lissac Brothers, visiteda laboratory in Colombes, France, where twoengineers with the lational Conservatory ofCareers were trying to produce lenses made ofPlexiglas resin cast in molds instead of usingheat compression. They used spring-actuatedmolds that allowed the mold walls to followthe retraction of the Plexiglas resin as itsolidified the material shrank 22 percentduring polymerization).SECOND ATTEMPT SU NGLASS LENSES

Following World War IT Georges Lissacbegan producing sunglasses using lenses madeof Plexiglas resin. In 1946, Sovis, a branch ofSaint-Gobain, transformed sheets of coloredPlexiglas resin into sunglass lenses by cuttingthe sheets into circles which were then heatedand pressed into plano lenses. Because thelens surfaces were parallel, tllis was arelatively easy way to produce lenses made ofPlexiglas resin.

TH IRD ATTEMPT PLEXIGLASRESIN M O LD E D T HR O UG H H E A T

The IGard lens process involved ofPlexiglas resin that ,,,ere compressed inheated iron molds. license for tltis processwas granted in 1937 to Peter Koch of Goreyn.Tllis was the process used by COIL in England.In 1946, another license was requested byArthur Kingston who also experimented withPlexiglas resin and polystyrene. Georges Lissacwas ulitially in favor of negotiating a license formolding lenses made from Plexiglas reSUl butchangedltis mind after talking to enguleerswho described the process used by COIL Hedidn t believe the COIL process was sufficientlyumovative. In 1950, a mechaIlic naInedBorulion received approval from Lissac tobegin production of lenses made fromPlexiglas resin. The lenses were reasonablyunpact-resistaI1t but very susceptible toscratching aIld yellowing with age. These earlyplastic lenses, called ORt\1A 500 lenses, wereused primarily for children.C R 9 RESIN MIL I TARYAND OPT ICAL USES

One day GraIldperret received a transparentsheet that seemed to have interestingmechanical and optical properties. Thematerial had good traI1Sparency and resistaIICeto scratclting 40 tiJnes that of Plexiglas resin.The commercial name was Homallte, and itwas made of CR-39 resin. The material hadbeen used as windows for AmericaIl taIlksduring the war. In 1953, Grandperret ordereda half liter of CR-39 reSUl for experiments

T he M en Who MadeLenses With CR 9Monomer A Real i ty

Robert K. Graham gconvinced that jJlastic lewere jJossible while worJor Univis Lens Comp

That vi ion became a rebut 0111) after ) earheartbreakingJailures

countless nights oj listento the sound oj breal

mold caused by heat fthe jJolymerizillg proc

t\oel Roscrow was making plastic lenseon a gas ring in a garage when he andhis grou.jJ Jormed Scientific OjJticalLaboratories oj Australia the companyIwowll worldwide today as SOLA. Upohis retirement Chainl /anDavi d L. Pacredited Roscrow s mix oj knowledgeentrejJreneurial drive, energy and sheercheell as contributors in helping achievthe comjJany s success.

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Grand/Jerret was 20 ears old when hest became involved in an attemjJt tooduce lightweight lenses from Plexiglasin in 94 Twelve years latel; hescovered some interesting sheets oj

ns/Jarent material that had been Used intanllS during World Har II The

terial was made oj CR 39 J9 resin, and hediately ordered a half liter oj materialppc Two ears later Lissac was

sun lenses Jrom CR 39 monomel:

TH E F IRST LENS M ADE W ITHC R 3 9 RESIN

Saint-Gobain accepted an order to delivercircular blanks made of Pyrex glass for usein building molds. Plastisol was used formaking gaskets to hold the molds. The processof polymerization was new to Grandperret speople and initially all the cast lenses brokeduring polymerization due to lack ofventilation. They soon discovered they had tofind away to control the rise in temperatureduring polymerization. the temperature rosetoo much the lenses turned yellmv and broke.On April 29 1954 for example they producedthree good lenses and one broken lens.Pittsburgh Plate Glass Co referred them to twopeople who had been working on plasticlenses for several years. One was a man namedJolm O Beattie; the other was Robert Grallatllin the United States. In June of 1954Grandperret spent three weeks in the UnitedStates learning the methods being used byGrahatll.SOLAR O R M A 1 LENSES

In 1955 IJssac Inc. decided to make sunlenses of CR-39 monomer. The resin wasordered a nd production methods similar tothose observed in the United States wereinitiated. There were still problems controllingpolymerization but eventually these wereresolved. nfortunately they had homogeneityproblems in the first batch of sun lenses. 1heresult was a variation in color.

O R M A 1 LENSES T HE U LT IM AT E GOAL

In the meantime matlY production methodsfor casting lenses with CR-39 resin weretried. One was suggested by Jolm O Beattiewhich involved partially polymerizing the lensand removing it from the mold to continuepolymerization in a large pan. Laterpolymerization in the mold was tried. Generalconsensus deemed that molding lenses withCR-39 resin would never be adaptable tobifocals. By this time both the English atld theFrench were convinced that the ultimateanswer would be a lens made of Plexiglasresin covered with a veneer of CR-39 resin forscratch protection. Gratldperret tried aradiochemical process for linking Plexiglasatld CR-39 resins but the resulting lenses wereunsatisfactory.

By 1959 however the company successfullyproduced ORM 1000 lenses with CR-39resin. In the early 1960s the COmpatlY beganexporting lenses to Germatly Spain Italy andSwitzerland. In Great Britain ORM Opticalopened in 1965 to produce prescriptionorganic lenses. The company s major successhowever was in the United States. Aproduction platlt under the name Silor openedin Florida in 1972. This facility wouldeventually become the largest producer oforganic lenses in the world.

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P RT THR

OPTIC L L OR TORIES

Converting lens production from glasslenses to casting lenses from CR-39monomer involved a variety of newtechnologies for lens manufacturers. It alsorequired new equipment and new employeeskills. For a number of years, most lensmanufacturers maintained two diverselydifferent production lines, one for glass andone for plastic. As lenses made from CR-39resin came to dominate the market, lensmanufacturers began dropping out of the glassmarket altogether.

Tllis changing market impacted opticallaboratories in even more dranlatic ways. Atthe tinle Armorlite began producing lensesmade from CR-39 resin, no labs had the abilityto surface plastic lenses. During the late 1940sand 1950s, a few progressive laboratoriesdistributed I-Gard acrylic stock lensespurchased from Mcleod Optical (see PlasticLenses, page 0). Labs learned to edgeplastic lenses, but they had no experience withgrinding and polishing them. Armorlite, thefirst successful manufacturer of plastic lenses,eventually (and secretly) set up a surfacinglaboratory to provide practitioners withsurfaced lenses. Armorlite was convinced tlliswas the only way they could create amarketfor their new plastic lenses

TH E P IED P IPER

By now, laboratories began to receiveoccasional orders for post-cataract la l sesmade from CR-39 resin. It seemed obviousthat labs would eventually have to surface thisnew material. As it turned out, the role ofconvincing and teaclling labs to process lenseswith CR-39 resin fell in the unlikely hands ofan ex-Canadian Air Force World War II pilotnamed Forbes Robertson. Robertson was hiredby Armorlite in 1959 to sell the company slenses. Iili tially, llis job consisted of detailingdoctors for ordering plastic lenses. The factthat many of the lenses Armorlite sold weresurfaced in their lab was, for the most part, adark secret. Robertson grew convinced thatthe only way to build national demand forlenses made from CR-39 resin was to get labssurfacing plastic lenses as quicldy as possible.His was aminority opillion at Armorlite, buteven ally he prevailed and was authorized toshow lab owners how to process lenses withCR-39 resill. Soon he began calling on evelYmajor laboratOlY ill orth America, hying toestablish amarket for Armorlite senli-fulishedlenses. Fil st, he had to teach labs how tosmface plastic lenses. His sample bag consistedof a few senli-finished blanks and a box of toxide.

It was the desire for lightweight, lligh plus,post-cataract lenses that created illitial interestin lenses made from CR-39 resin. This came

Forbes Robertson was convinced the onway to malle lenses with CR 39 9 resinsuccessfu l was to get laboratories involThe hundreds of sales l it he madec n lingfew lens blanlls nd a can ofoxide resulted in JJwn} major wholesalaborat 1ies biting the bullet nd becoinvolved in plastic lens jJroduction

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mostly from large wholesale and retailorganizations such as Benson Optical,Uhlemann Optical and others who had largenumbers of ophthalmologists as customers.Ophthalmologists wanted their patients to havethe new lightweight cataract lenses theylearned about at the Academy ofOphthalmology (from Armorlite s Bob Graham,who lectured on lightweight lenses made fromCR-39 resin at Academy meetings).

Among the first companies to take upplastic surfacing at Robertson s urging wereUhlemaIU1 Optical and Boll Lewis, twoprominent Chicago retail orgaIlizations, andWllite Haines, major wholesale laboratorychain based in Ollio. Around that same time,Robertson heard that the three partners atParaIll0unt Optical in SaIl FraI1Cisco werebreaking up, and one planned to set up laboratOlY in PortlaIld, Ore. He flew toPortlaIld aIld called on Lawrence LarryWheelon. He gave Larry and llis partners, OttoWagner and son Robert Wheelon, llis standardpitch on the advaIltages of processing plasticlenses, aIld left town without knowing whetherllis sales efforts worked.

1\vo weeks later he received call fromWheelon with the astOllishing. news that thepartners decided their new lab, called OptiCraft, would process only plastic lenses. LanyaIlIlounced that he and llis partners WaIl ted tocome down to Pasadena aIld spend week

The only source for teclmical heltime was Armorlite, and it turned out tnat theyhad only just started surfacing. n Wheelon words, it was the blind leading the blind.During llis visit to Armorlite, Wheelon toldGrahaIll he waIlted to be GrallaI11 S bestcustomer. Grallam responded by offering llim job, but Wheelon decided that Pasadena wasno substitute for the natural charms of thenorthwest and PortlaIld. He returned toOregon, and Opti-Craft soon becanleArmorlite s best customer. Opti-Craft s salesefforts, in effect, opened up the whole WestCoast for Armorlite. Other wholesalelaboratories began surfacing plastic lenses intlle hopes of salvaging business tlley were losingto Opti-Craft. (See The First All-Plastic Lab,page 30)LENSES M DE FROM CR 9RES IN INTRODU ED T THE OL

The 1961 Optical Laboratories Association OLA) convention in Chicago was majorevent for Robertson. This would be the labsillitial introduction to lenses made from CR-39resin. Sillce Armorlite hadn t sold senlifilushed lenses before, there was madscraIllble to get lens boxes printed so thelenses could be displayed at the OLA ill

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reasonably professional way On the way to theLos Angeles airport, Mrs. Robertson hung overthe back of the car seat tlying to match andinsert lens blanks into the proper printedboxes. She managed to sort the lenses and boxthem by the time they reached the airport. ThatOL convention paved the way for theindustry s slow transformation from glasslenses to lenses made from CR-39 resin.

OTHER L EXPER IENCES

Another early convert who responded toRobertson s sales efforts in positive way wasBill LowLY of LowLY Optical in Florida, lablater acquired by Milroy. Aggressive labsacross the countLy began experimenting, tryingany way they could think of to surface plastic some ways were rather bizarre). William CSeibert, owner of Three Rivers OpticalCompany in McKees Rocks, Pa., remembersthose days well. In the mid-1950s, he workedfor American Optical as lab supervisor. Mostmachinely used in American Optical labs wasmanufactured by Obut was hardlyconsidered state-of-the-art, even for that days demand for lenses made from CR-39 resin

increased, American Optical fell behindindependent labs in processing plastic lenses.Seibert remembers the tortures of tlying todevelop techniques for grinding plastic lenses.

Wire mesh pads were tried with 145 gritemery, resulting in 30 minutes fining for eachlens. Polishing was done on white felt pads

Seibert s Anlerican Optical branch never didreach point where they could produce plasticlenses with the ease of glass. Problemscontinued in one form or another until1975-76 when American Optical installedCoburn surfacing equipment. Even with thenew equipment, they were still plagued withwaves and distortion. Evennlally theydiscovered yellow felt pad from Econ-o-cloththat worked. They tried one-step pads,two-step pads and even diamond pads. It was conunon experience to produce one good lensand discover they were unable to repeat theprocess for the other eye. Lenses ended upwith gray edges or swirl marks. It wasn t at allunusual to produce good-looking lens thatcouldn t be read in the lensometer.DIFFERENCE ETWEENGL SS N D P L S TIC

Most surfacing problems were created, inSeibert s opinion, because labs wanted toprocess plastic the way they did glass.Surfacing blocks were small in diameter anddesigned for glass, offering no support beyondthe center of the lens. Plastic lenses flexedduring surfacing, creating multiple waves anddistortion. Sales engineers at Coburn Opticalwere helpful during this period, but evenCoburn was feeling their way in this new field,much like their customers. Eventually, Coburncame out with larger blocks and eliminatedone cause of distortion.

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POST C T R CT LENSES

Agood set of glass molds, however, couldreplicate the most sopltisticated asphericcurves over and over in CR-39 resin. It wascomparatively easy for labs to convincedoctors arld consumers of the advantages oflightweight plastic lenses for cataract patients.Labs found this a ready market arId beforelong, labs were scattered around the countrythat routinely surfaced plastic cataract lenses.Expertise gained with cataract lenses helpedestablish plastic lenses for all patients.

The fate of glass lenses was largely sealedwhen the Food and Drug Administration (FDA)decreed in 1972 that all glass lenses sold in

TH E F IN L STR W

llti tially, labs concentrated their plasticproduction on producing post-cataract lenses.Plastic lenses were too new arId too prone toscratching for most patients. With post-cataractpatients, it was a different stOlY During thatperiod before the development of inter-ocularlenses, two factors made lenses casted fromCR-39 resin an ideal lens for post-cataractpatients. The first was weight. Strong pluslenses of IOta 14 diopters were eX1remelyheavy when made up in glass, a situation thatconcerned every wearer of these awkwardlenses. The second factor was the recentdevelopment of sophisticated aspheric postcataract designs that proved extremely difficultand costly to produce in glass.

One day Forbes received a call from AllanKosh, father of Jeff and Stuart Kosh. KoshOptical (then in ew York City) had been arlearly convert to CR-39 resin. Allan calledcomplaining about a rash of surfacingproblems that had recently cropped up. Forbessaw on TV that morning that a heat wave hadltit ew Y ~ r k City He asked Allan he airconditioned the lab as he had prontised. Theanswer was, at yet. We have the equipmentordered but t s not installed. Forbesreminded ltim how heat affected plasticsurfacint eedless to say Allarl quickly hadthe air conditioning equipment installed.

Forbes Robertson was convinced that plasticlenses would only succeed labs couldprocess them on equipment they alreadyowned. The problems carne in convincing labsthat to do this, they had to completely cleanthe existing equipment and maintain a degreeof cleariliness they weren t used to. Labs in theearly 1960s looked far different tharl today slabs. Robertson s greatest problem was simplytheir dirty condition. He undoubtedly offendedsome labs when he told them, The first thingou have to do is clean up. Another issue wasthat t created many problems related to

~ ~ l J l ~ ; a g plastic. ir conditioned labs wereco p r tively rar that tinle, arld Robertsoncontinually ur that plastic production lines

e tioned. Eventually, tItis wasced labs. They begarl totic on separateair conditioning for the

Lenses madefrom CR 9 9 resin were themajor influence on e;eglassfashionsuring the seventies n eighties. Theirlight weight made stunning oversize

mes a reality. The profusion of solidn gradient tints of ever hade nhue that could be jJroduced throughartistic tinting of the lens made those ,ears unforgettable to those who livedthrough them.

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T HE FIR ST L L P L S T IC L B

n June, 1962, Lawrence Wheelon, anexperienced lab man with more couragethan most lab people of that day, decidedthere was a rosy future for plastic lenses.Wheelon had an aunt who underwentcataract surgelY at the University ofWashington. Her new plastic cataract lenseswere ordered from Armorlite. took threemonths to get them. WheelQn decidedanything that difficult to obtain would be agood business to get into. Along with IllS wife;IllS son Bob; Steve Willtman, an experiencedlab man who had worked for Riggs Optical;and Otto Wagner, an experienced surfaceman, Wheelon set up a new laboratOly inPortland. Equipment was purchased from arecently-closed la b in Montana.

Wheelon initiated a relationship with PPGand investigated the possibilities of castinglenses. By the time PPG engineers pointedout all the ramifications required to castlenses, \Vheelon decided t made more senseto fabricate lens blanks cast by someoneelse. FolloWing a sales call from Armorlite sForbes Robertson, he flew to Pasadena andmet with Bob Grallanl. When the Opti-Craftlab opened, they made lllstory by beconllllgthe first plastic-only laboratOly.

Footnote: CustOtners liked Opti-Craft sservice and wanted to order all theirlenses from the same source. Thesedoctors weren t, howeveJ; ready to switchfrom glass to plastic for conventionallenses. Within ayeal; Opti-Craft facedreality and set up a separate division forprocessing glass lenses. As the yearspassed, howeveJ; Opti-Craft eventuallyconvinced customers o the advantages olenses made from CR-39 resin, and thecompany became a leading laboratoJJ onthe West Coast. They are presentlypart othe Omega LaboratoJJ Group, a divisiono Essilor o America. For slightly less thanayeal; however Opti-Craft was the onlyall-plastic lab in the UJorld

the United States would have to be a minimumof 2.2 mm at their thinnest point, be heattreated or chemically tempered and pass adrop ball test performed by the lab theperson edging the lenses. Previously, mostglass lenses had centers or edges dependingon the power) well under 1.5 mm, some withcenters as thin as 1.0 mm. Tllis new rulingeffectively meant that glass lenses would be 30to 50 percent heavier than in the past.

Tllis couldn t have happened at a worsetime for glass because frame styles were juststarting to grow in size. These factorseffectively combined to give lenses made fromCR-39monomer the boost that wouldultimately make CR-39 resin the dominant lensmaterial in the United States. The rest, as theysay, is llistory.

wing the seventies and eighties, thone item on evelyone s olJtical wishlist was a lightweightjJlwtochrollliclens that would work. SeveraljJromisphotochmmic jJlastic lenses showed tdUTi ng the eighties but none oj themsatisfied the jJroJessions eXjJectationstool the introduction oj Tra:nsitionSlenses in to satisf) the need.Instead oj replacing glass photochrolenses (less than jJercent oj themarl

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T h e St ory hot ochro nicPlas t i c ens e sTHE CONT INU ING EVOLUT ION C R 3 9 RESIN

Almost from the day photochromic glasslenses were first introduced, lensmanufacturers received requests for photochromic lens made in lightweightplastic. From the mid-sixties on, evel)gathering of optical people would usuallyinclude discussions of, When are we going tohave plastic photochromic lenses? During theentire fifty years CR-39 resin has been usedfor ophthalmic lenses, PPG researchers havecontinually searched for ways to increase itsversatility. The most dramatic result of thiscontinuing research was the development of aneffective photochromic process based on variation of CR-39 resin called CR 3 7monomer. The StOl) of how the Transitionslenses process evolved is best told in timelinefashion, beginning in 1973. 9 7 3

The first reported work on photochromicsby PPG takes place at the cOQ lpany s BarbertonTechnical Center in 1973. From then until1980, photochromic research developmentbecame part of number of different CR-39monomer projects. These efforts remained

comparatively low-key, and no synthesis of newcompounds was involved. 98

American Optical introduces their Photolitelens. The industt) excitement prompted by thisproduct release galvanized the scientists at PPGinto another flurry of photochromic research.The American Optical lens turns out to be commercial failure because of poorproperties, short lifetime and an unattractiveblue color. new specialist with backgroundin photocluomics is added to PPG s staff, andsynthesis of new photochromics combinedwith testing of known photochromics in matrixfrom CR-39 monomer begins. 9 8 3 PVRIDOBENZOXAZINES

This year is photochromic milestonebecause of the discovel) of new family ofphotochromics called pyridobenzoxazines.This year also marks the discovel) of theunique inlbibition process for incorporatingphotoclu omic properties in polymers andcopolymers made from CR-39 monomer. 9 8 4

PPG starts joint venture with IntercastEurope to manufacture and sell photochromicsunlenses called Attiva. These are stillmanufacnlred by Intercast, using PPG s blue

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photochromics. Research in this teclmologycontinued, and by 1985, production of Attivalenses reached 3,150 per day In 1986,marketing of the Visenza lens, an all-PPGventure, begins. variety of prototype lenssystems were produced and tested on PPGemployees and consumers during the nextthree years.986 TRANS IT IONS

PPG authorizes 1 million for testing thetechnical and marketing feasibility of plasticphotoclu'omic lenses. Between July 1987 andMay 1988, the company assesses theacceptance of prototype lens systems throughemployee and consumer use tests. In the fall of1987, 30 persons wear the lenses for onemonth. typical comment about thoseprimitive lenses comes from one wearer, Theyworked pretty well... could get lot darker,and, boy, are they an ugly yellow in thebleached state. In 1988 pair is given toanother employee to wear on trip to Hawaii.His comment: f you can't make them get anydarker, you're out of business. Additionalconsumer-use tests are conducted inMitmeapolis, Miami and San Diego, andgradually, the consumer responses improve.

988

On May 1, PPG gives the go-ahead toproceed to the next step which o s ~ s t s ofsetting up test markets for the newphotochromic lenses. This is considered milestone by the company's ophthalmicphotochromics group, and special picnic isheld at Lake Dorothy, Ohio, near PPG'sBarberton Technical Center. Eighty-eightpeople show up for special catered meal ofbarbecued ribs. Shortly after the picnic, PPGProject Director John Crano hand-carries 100lenses to Vermont and southern ewHampshire for the first tests. Later, additionaltest markets are established in Memphis andPittsburgh.99

Substantial progress is made, and by 1990,Transitions Optical Inc. (TOl) is formed and manufacturing facility established in PinellasPark, Fla., for producing photochromic lenses. ythis tinle, PPG invested more than 8.5million in developing the new Transitionsphotochromic lens.

To firm up the industry's shaky confidencein such new technology, TOI wisely decidesto offer patient satisfaction guarantee on

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their new lenses. During the first three years ofdistribution, their return rate runs less thanone percent, remarkable record for such new technology.

The technology used to producephotochromic plastic is totally different fromphotochromic glass. The chemistry is based onorganic, rather than inorganic, compounds.When Transitions lenses are exposed to theultraviolet rays in sunlight, the photochromiccompound is activated to form that absorbsvisible light, causing the lens to darken. Whensunlight is removed, the photochromiccompound converts back to its colorlessform, and the lenses return to their originalclear state.

Other plastic photochromic lenses haveeen introduced, but none have enjoyed theccess of Transitions comfort lenses, datingto their introduction in 1990. Transitions

are made of lightweight polymer,to CR-39 resin.

While their technologies are completelydifferent, photochromic glass andphotochromic plastic share certainharacteristics. Both are activated by the

violet component of the solar spectrum.Both photochromics are temperaturedependent. Another distinct advantage ofphotochromic plastic compared to

photochromic glass is that Transitions lensesdarken uniformly, regardless of theprescription of lens design. Thicker portionsof photochromic glass lenses darken morethan thin areas, creating an unattractive,uneven density.99

The first Transitions lenses formulation isreplaced by the new Transitions Plus. Thissecond generation provides greater activationspeed, darkening more and faster than theoriginal lens. 1993, Transitions Plus lensesreceive the prestigious Optical LaboratoriesAssociates aLA Award for Best Lens Treatment.996

The newest generation of Transitionslenses is unveiled to the eyecare professionthrough series of galas held in major Ucities. The result is overwhelming approval ofTransitions III lenses which darken faster,darken more and achieve true gray colorthat most consumers prefer. This newest lproduct is also available in mid-index,opening totally new market forphotochromic plastic lenses.

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TH E EN D N OT YET IN SIGHTTH E IMPORTANCE POSIT ION ING

t the time Transitions comfort lenses\\ere introduced the lens market in thenited States was approximately 80 percent

plastic and 20 percent glass. Half of all glasslenses sold were photo chromic. With theintroduction of Transitions len es manydoctors and dispensers assumed the marketfor these new lenses would be those patientswho had been \\ earing heavy photoclu onlicglass (10 percent of the market).

Marketing people at TOI thoughtdifferently. Go after the consumers whoalready wear plastic lenses (80 percent ofthe market), and go after those who wearfixed tints (60 percent of the market) ,wastheir advice. That huge untapped segment ofthe market hlrned out to be exactly right forTransitions lenses. Further, offering theseconsumers photochromic lenses opened upa completel) new premium lens market forthe eyecare profession. The rest is historyTransitions lenses hlrned out to be the mostsuccessful and fastest-growing segment ofthe entire premium lens field all madepossible because of proper positioning of abrand new technology.

With the experience of ty years of majorparticipation in the ophthalmic l n ~ i n u s t r ywhat does the future in this important segmentof the health care industry hold for PPG

Some industry observers have tracked thesteady growth of alternative plastic lensmaterials such as high index and polycarbonate,and have predicted a gradual decline of marketshare for lenses made of CR-39 monomer.Executives in PPG s optical products businessare quick to point out that the market for lensesmade of CR-39 resin has never been stronger.Willie usage in the nited States has flattenedsomewhat, continuing conversion from glass toCR-39 resin is rising dramatically worldwide.They remind listeners that major highlypopulated countries such as India and China arejust at the threshold of a major conversion fromglass to plastic. The general expectation is thatthis trend added to all the third-world countriesentering a similar conversion phase predictshealthy increases in worldwide sales of lensescast from CR-39 resin for years to come.

John Crano, PPG s associate director ofoptical products, was asked recently what hesees in PPG s future for the optical productsbusiness. Our initial major contribution to theophthalmic industty was the development ofCR-39 monomer-chemistt that ultimately

The one individual at PPC whojJersonally involved in the questfojJhotochromic plastic lens from thestart wasJol1l1 Crano. Once his rchemist were convinced that theyfound the answel; a jJrimitive j roline was set 1Ij andJohn j ersollcarried the first lenses jJrodu eta Site Labs inVermollt andHamjJsh ire.

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became the major substrate for ophthalmiclenses in every developed countty. scontinuing investment in technology led to thedevelopment of photochromic Transitionslenses. This lIe\\ technology has ah eadyproved to be a major profit contributor for theeyecare professions.

To quote Peggy Lee, Dr. Crano was askedIs that all there is? He laughed andproceeded to project. some of the areas inwhich he believes PPG \\ill playa major role.Dr. Crano contemplates higher index materialsfor Transitions lenses and suggests those couldinclude polycarbonate. There is a viablemarket for more easily cured high indexsubstrates utilizing ultraviolet UV light forcuring. This is an area that will certainly beconsidered. Development of -cured highindex resins will lead to more cost-effectivemanufacturing and this will ultimatel benefiteVel One in the supply chain frommanufacturer to consumer. The developmentof modified CR-39 resins that will producethinner lenses in 1.50 index with improvedimpact resistance are definitely underconsideration.

Whether Dr. Crano s predictions come topass or not, PPG Industries llfs proven thevalue of their contributions to the eyecareprofessions and the spectacle-wearing publicduring the past fifty ears. \\ ould befascinating to have the b i l i ~ to project into

the year 2047 and observe how celebratesthe lOath amllVerSal of their majorcontribution to mankind and the field ofophthalmic optics.

PPC headquarters are based ill the worldJa11l0u ix buildillg gla c011l/Jlex located atOlle PPC Place ill Pittsblllgh O/Jelled ill 1983alld de iglled b rellowlI architect Phili/JJohll 011 thi totally ellerg -eJJiciellt buildillg habec011le a Pellll Iva Ilia la lid11Iarl

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TH E EVOLUT ION LE NS ES M AD E W ITH C R 9 M ON OM ER

1938

1937

1941

194

Combined Optical In@lstries Ltd. COIL) starts production of IGard lenses made fromPlexiglas resin.TULCA The Unbreakable Lens Company of America) begins producing injection-moldedlenses made from PMMACR-39 monomer developed by research team at Columbia Southern ChemicalCompany, wholly-owned subsidialY of Pittsburgh Glass Co now PPG).PPG researchers discover CR-39 resin and apply for patent. They discover the materialcan be combined with paper, cloth, pigments and other materials, and molded intofinished, shaped, laminated products.CR-39 resin used for producing transparent gauge tubes in aircraft to prevent breakageand fuel spills associated with glass tubes.France s ational ConservatOlY of Careers tries casting Plexiglas resin in spring-actuatedmolds.CR-39 resin first used for reflector and searchlight applications.CR-39 monomer patent awarded to PPG s Irving E Muskat and Franklin Strain.Univis closes their plastic lens division.Robert Grahanl and ex-Univis team move to California.Lissac produces sunglass lenses from flat circles of Plexiglas resin pressed intoplano lenses.Armorlite Corporation forms and begins experinlenting with CR-39 resin.McLeod Optical becomes exclusive S distributor for IGard lenses.Lissac sets up to produce lenses made from Plexiglas resin in France.LOS introduces ORMA 500 lenses made from Plexiglas resin in France.Lissac s Rene Grandperret orders half liter of CR-39 resin for experiments.Grandperret spends three weeks in the S with Robert Grallam.Lissac s Bernard Mignen successfully polymerizes lenses made from CR-39 resin.Lissac, Inc. makes sun lenses from CR-39 monomer.ORMA 1000 lenses made from CR-39 resin introduced worldwide.First plastic bifocals are cast.SOLA Optical formed and begins producing lenses made from CR-39 resin in Australiawith 10 employees.

1961 66 SOLA begins exporting lenses made from CR-39 resin to Japan, England, France, Italy,India and other countries.SOLA s Japan operation opens the first totally foreign-owned operation in Japanfollowing World War II). SOLA introduces Spectralite optical lenses, the firstphotochromic high index lens

1968

19471949195195219531954

19431946

19551959196

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1969 La Lunette de Paris introduces ORMA 1000 lenses to the United States.Lenses made from CR-39 resin tested on U S pilots.

197 SOLA s UK operation opens.1971 Food Drug Administration passes impact-resistance regulations for

eyeglass lenses.Signet Uptown begins casting bifocals, trifocals and post-cataractlens blanks.

1972 Silor opens lens casting plant in Florida.1973 PPG s Barberton Technical Center conducts the first photochromic

experinlents with CR-39 monomer.1974 3M develops scratch-resistant coating for l