Vision Screening Why? Tools of the trade

Vision Screening

•Why?•Tools of the trade

Why?

1. Law

1.Vehicles (cars & heavy duty)Regulation 102 of the National Road Traffic Act (93

of 1996)

2.Driven machineryDriven machinery regulations (Feb 2005) of the

Occupational Health & Safety Act

2. Employee productivity

– Clear & comfortable vision

– Headaches, neck aches

Why?

Regulation 102 of the National Road TrafficAct (93 of 1996)

Codes A1 to EB (light vehicles):

• 6/12 in each eye•One eye worse than 6/12, other 6/9 or better

Codes EC & EC1 (heavy duty vehicles):

• 6/9 in each eye•One eye worse than 6/9, too bad…

Minimum visual acuity

Regulation 102 of the National Road TrafficAct (93 of 1996)

Minimum visual fields

Codes A1 to EB (light vehicles):

• 70° temporal each eye•One eye < 70°, at least 115° total horizontal field (both eyes together)

Codes EC & EC1 (heavy duty vehicles):

• 70° temporal each eye•One eye < 70°, too bad…

Driven machinery regulations

• Same as for codes EC & EC1 (heavy duty)– 6/9 each eye– 70° temporal visual field each eye

PLUSStereopsis (3-D vision)

• Existing PDP– Same as codes EC & EC1 (no stereopsis

required!)

Tools of the Trade

All-in-one vision screeners

Keystone vision screener

Keystone Telebinocular

All-in-one vision screeners

Pro’s

•Visual acuity (far & near)•Stereopsis•Colour vision•Muscle balance

All-in-one vision screeners

Cons

• Patient observation more difficult, eg. squinting or viewing through incorrect part of spectacles

• Stereopsis test difficult to explain• Proximal accommodation

Tools of the trade

Visual acuity

Snellen chart

1800’s – stood test of time

Wall chart

Chart projector

Correct use!!

•Test distancesee ‘Eye Care Topics → Visual Acuity’ on www.occuvision.com

•Gentle eye cover•Watch person for cheating

Snellen chart

Colour vision

Ishihara plates

-Simple

Colour vision

Farnsworth D-15

Good adjunct to Ishihara

Stereopsis

Randot stereotest

NB presbyopes towear near visioncorrection

Autorefractor

• Refractive state of eye

• Keratometry– Measures basic

corneal curvature

Non-contact tonometer

Intra-ocular pressure• Glaucoma• Peripheral field loss

> 42 <42 > 2 Yrs < 2 Yrs or N/A

> 0.75 D

< 0.75 D

YES

NO > 21 mmHg

< 21 mmHg YES NO

Age of employee

Age of Spectacles

Tonometry

Snellen VA in best eye worse

than 6/9

Ametropia (habitual)

Myopia, Hyperopia, Astigmatism

spectacles

PASS.

RETURN TO WORK

FURTHER

EVALUATION NECESSARY

Near vision , esp. at night; Frequent

temporal & frontal H/A’s; Asthenopia

Thank you