High-mountainsun protection

www.julbo-eyewear.com

CONTENTS

1. Introduction

2. The dangers of the sun in high-mountain environments

3. The most common disorders

4. Julbo sun solutions

Anyone who practices high-mountain sports must be aware that they are operating in a risky environment.While the risks linked to the mountains themselves may be obvious, those caused by exposure to the sun at high altitudes are more difficult to understand. Julbo sheds some light on the subject.

Since the 1950s and the release of its famous Vermont, Julbo sunglasses have accompanied expeditions up all the mountains of the world. From the Antarctic to the Alps to 8,000 m Himalayan peaks, Julbo has honed its expertise in high-mountain sun protection to become a benchmark brand in this area.Julbo shares its experience to make sure you have the best possibleprotection for high-mountain environments.

2. THE DANGERS OF THE SUN IN HIGH-MOUNTAIN ENVIRONMENTS

Exposure to solar radiation increases on average by 10% (between 4 and 16%) with every 1,000 m of altitude, and the UVB light it contains is particularly dangerous.

In addition, the snow often present in the mountains reflects between 80 and 90% of solar radiation compared with 20% on non-snowy ground.

The intensity of solar radiation is therefore 1.5 times greater at 2,000 m and 2.5 times greater at 4,000 m than at sea level.

Exposure will vary depending on the thickness of the ozone layer in the atmosphere (which acts as a natural filter), the season and the angle of incidence of the sun's rays.

It should be noted that solar radiation is 25% greater at the autumn equinox than the spring equinox when the ozone layer is thicker.

The ozone layer varies in thickness depending on where you are in world and therefore offers differing degrees of protection.

The amount of radiation varies as the sun's position changes during the course of the day. The risks linked to light will therefore also vary.

The angle of incidence of the sun's rays when they penetrate the ozone layer has a direct effect on the amount of filtration provided by the ozone.

It is for this reason that radiation is strongest between 10 am and 3 pm.

It is important to remember that in cloudy conditions the sun is still dangerous in the mountains.

You should not count on overcast skies to protect you as they provide only limited filtration. While UV light can be stopped by some clouds (alto-cumulus), cirrus clouds have no filtration effect at all.

50% of the sun's radiation passes through fog. It is therefore necessary to protect yourself in the mountains, even when conditions are cloudy.

At high altitude, in overcast conditions, you may frequently find yourself in the upper layer of the clouds. The radiation here is intense through the effects of light diffraction. The risks are therefore even higher than in fine weather.

3. THE MOST COMMON DISORDERS

Photokeratitis or snow blindness

Cause: Erosion of the epithelium (layer of surface cells) covering the cornea resulting from extended exposure to intense light (high UVB radiation).

Symptoms: 4 to 6 hrs after exposurePain and "grains of sand" sensation under the eyelids together with photophobia (pain increased by light).Conjunctival redness, excessive tear secretion, swelling of the eyelids and difficulty opening the eyes, as well as intense blepharospasm (involuntary blinking of the eye).

Treatment: rest in a dark room / eye patch / application of antiseptic eye wash and ophthalmic ointment.

Avoid eye washes containing anaesthetics.Contact lenses must not be worn for 4 to 5 days.

Erythropsia

Cause: Exhaustion of the retina resulting from prolonged exposure to intense light stimulation. This disorder is rarer than snow blindness.

Symptoms: Objects take on an abnormal reddish hue.

Treatment:● rest in a dark room● eye patch● application of antiseptic eye wash and ophthalmic ointment.

Snow blindness and erythropsia do not have long-term after-effects if treated in time. However, snow blindness can endanger the lives of mountaineers in high-mountain environments by depriving them of their vision.

White-out syndrome

Cause: frostbite of the eye or eyelids as a result of being in extremely cold conditions.

Symptoms: Initial symptoms: pain, blurred vision, photophobia and excessive tear secretion, or even total loss of vision.

Later symptoms: reduced visual acuity associated with a loss of perception of relief and elevation resulting in disorientation and sensations of vertigo.

Treatment: protecting the eyes from cold and warming them up should ensure good recovery.

Corneal frostbite

Cause: the temperature of the cornea is between 29 and 36 °C. Extreme cold and/or snow combined with wind can lead to frostbite of the cornea.

Symptoms: blurred vision, excessive tear secretion, photophobia or even total loss of vision.

Later symptoms: reduced visual acuity associated with a loss of perception of relief and elevation resulting in disorientation and sensations of vertigo.

Treatment: eye patch and gradual passive heating and removal from cold (2 to 3 days).Expedition tip: use a warm teabag to heat up the eye.

Warning: corneal frostbite can lead to necrosis and loss of the eye if not treated correctly.

4. JULBO SUN SOLUTIONS

All these disorders can be prevented by wearing equipment suitable for the conditions.

Julbo has developed a range of products specially adapted to these extreme conditions with category 4 lenses, wraparound frames and protective side shields.

4 // Julbo lensesIn high-mountain environments, a high degree of sun protection is necessary and you should opt for category 4 lenses.

Julbo offers the following lenses for these conditions:

Cat. 4 mineral lens (VLT*:7%). The must-have product for glacier frames. The only lens to offer complete protection in very high mountain environments. Recommended for individuals sensitive to infrared light

Cat. 4 polycarbonate lens (VLT* :5%). Designed to offer powerful protection for mountain trekking and mountaineering

*Visible light transmission

4 // Julbo lenses

Cat. 2 to 4 NXT© photochromic lens (TLV*: 20-5%). The brown tint and filtration level have been designed to offer the best performance for trekking and mountaineering. NTS technology guarantees a constant photochromic range, whatever the outside temperature

Cat. 2 to 4 NXT© photochromic lens (TLV*: 42-7%). Lighter than the Cameleon lens and suitable for skiing and trail running. Offers good protection at low temperatures in high-mountain environments.

4 // High-mountain sunglasses

High-mountain frames must provide the wearer with optimum protection. In addition to the category 4 lens, they must offer good protection against direct and indirect radiation as well as external elements. They must also be adapted for use in extreme sports.

A good frame must therefore provide:- Total coverage / protective side shields.- A pronounced curve.- Excellent grip.- Ideally a headcord.

4 // High-mountain sunglasses: EXPLORER

The highest mountains and extreme conditions bring out the best in these sunglasses developed in collaboration with the elite climbing school in Chamonix.

The Explorer takes glacier sunglasses to the next level: lenses with impressive protection, coverage from damaging UV rays, an anti-fog ventilation system and side shields to stop wind and snow getting in.

Available in an Alti Arc mineral lens, Cameleon photochromic lensand Spectron 4 polycarbonate lens.

4 // High-mountain sunglasses: TREK

Trek's mission is to provide highly technical but light equipment for moving fast in extreme environments and achieving optimum performance.

It combines the fundamental principles of mountaineering glasses with the lightness and ergonomics of speed sport sunglasses.

The side shields block radiation in high glare environments such as glaciers and deserts, while the suspended lens ensures clear vision and good ventilation.

Available with Cameleon or Zebra lenses for optimum protection from intense solar radiation.

4 // High-mountain sunglasses: BIVOUAK

The Bivouak has been designed to cope with a huge variety of terrain and is suitable for every outdoor activity.

With wide Cameleon or Zebra lenses and optimum coverage provided by the magnetic side shields, these glasses offer protection specifically adapted to mountain use.

4 // High-mountain sunglasses: MONTEROSA/MONTEBIANCO

With removable side shields, wide lenses and ergonomic design, MonteRosa and MonteBianco offer total protection.

These frames combine style and simplicity with lightness, technical excellence and outstanding protection, giving users high-performance mountain glasses that are also suitable for everyday use.

4 // High-mountain sunglasses: TENSING M/L

The ultra-wrap profile of these glasses provides ideal protection against high-altitude sun while the side openings guarantee superior ventilation.

These glasses offer excellent value for money and have been designed so that amateur mountaineers can enjoy their sport in complete safety.

JulboRue Lacuzon

39400 Longchaumois - FranceTel.: + 33 (0)3.84.34.14.14

info@julbo.fr

www.julbo-eyewear.com

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