Sunglasses: beach, driving, which category to choose?

THE sunglasses are essential to protect the eyes solar radiationmainly visible light and ultra-violet (UV). Summer or winter, beach, city or mountain, fragile eyes or not… Everyone should wear sunglasses whenever… it’s sunny. But how to choose them well ? Which category to be well protected? 1, 2, 3, 4? To drive ? When to wear polarized glasses? Advice from Pierre Cesarini, director ofSolar Safety Association.

Why should you wear sunglasses?

Sunglasses provide eye protection with two distinct purposes: comfort and health. “In terms of comfort and quality of vision, sunglasses serve to reduce glare and are especially useful for people who work outdoors or those who engage in outdoor activities“, says our specialist. And to properly reduce glare, the glasses must be sufficiently tinted (defined by the CE category of protection, see below). Sunglasses are also used to protect from ultraviolet rays and to prevent the ocular pathologies. These are essentially long-term pathologies, such as cataract which is favored by chronic exposure to ultraviolet rays (it is estimated that 20 to 25% of cataract cases are linked to unfiltered exposure to UV rays). Another risk related to UV but probably during exposure to higher intensities of radiation (stays in the mountains, at sea): AMD. “It would seem that UV exposure contributes to the appearance of AMD, with of course other risk factors (smoking, lack of antioxidants in the diet, etc.). This kind of UV exposure (UVB in this case) also promotes the risk of ophthalmia (also called sunburn of the eye) which corresponds to a burn of the cornea. There are also other risks, which are nonetheless rarer, such as the pterygiums (a thickening of tissue that grows from the conjunctiva)”, continues our interlocutor.

Which category to choose for sunglasses?

There is a European regulation which determines the category of protection of a pair of sunglasses based on lens tint. But for all categories, the regulations provide for a minimum level of protection against ultraviolet rays. There are 5 categories: 0, 1, 2, 3 and 4. according to the increasing percentage of filtered light:

• Ia category 0 associated with the symbol of a cloud corresponds to transparent glasses or almost. “They should not be called sunglasses because they do not filter or very little. Put it or nothing, it’s the same“, indicates our interlocutor.
• categories 1 and 2 correspond to glasses which are slightly tinted, adapted to rather average solar luminosity. “There are rather few situations where we can recommend these glasses“, warns Pierre Cesarini.
• category 3 corresponds to well-tinted glasses, which allow between 8 and 18% of the light rays to pass. “This is the most common category. This is the one we generally recommend. because it suits most of us in just about any situation“, he indicates.
• category 4 corresponds to very strongly tinted glasses. They only let in between 3 and 8% of light. This is the category that we recommend when you are in the mountains (snowy) or on a boat. On the other hand, they are prohibited while driving.

These protection categories also apply to spectacles with photochromic lenses which are clear (or nearly transparent) lenses that darken automatically when exposed to sunlight.

The category must be expressly indicated on the pair of glasses (usually on one of the branches). Compliance with the regulations results in the visible, legible and indelible affixing of the “CE” marking followed by the protection category, can be read on the website of the Directorate General for Competition, Consumer Affairs and Fraud Prevention. “In Europe, it is a mandatory mention whatever the distribution channel: at the optician, on the internet, in supermarkets…”says our interlocutor.

What category of sunglasses for driving?

“For driving, we choose a pair of category 3 glasses with polarized lenses to protect against reverberation“, advises our interlocutor.

What category of sunglasses for the mountains?

In the mountains, where the light is particularly strong, it is advisable to wear category 4 glassesideally also polarized.

When to choose polarized sunglasses?

THE polarized glasses are useful when there is reverberation (light is reflected off smooth surfaces such as water, glass, snow or smooth road surfaces): for example, for driving (especially if the sun is low), for water activities (sailing, boat…) or in the mountains. Polarized lenses will block the reflection of light and provide a clearer, more contrasty image. “In situations where there is strong reverberation, sunglasses should be considered a safety accessory“, assures the expert.

What shape of sunglasses to choose?

“The shape is a point on which we do not insist enough when choosing sunglasses. However, the shape is almost as important a parameter (or even more) than the quality of the glass.“, insists Pierre Cesarini. It is advisable to choose an enveloping shape so as to protect the sides of the eyes. “There is also the risk of not wearing sufficiently enveloping glasses, it is to have a light source behind you which reflects on the glass, bounces and hits your eye. There are also glasses provided to absorb and avoid this rebound effect“, he continues. Prefer wide frames (which ideally cover the middle of the nose to the top of the eyebrows) to protect the eye and around the eye. Beware of round glasses, which are worn on the front of the nose, and which allow light to pass above and below the glasses.

Should you only wear sunglasses in summer? Or all year round?

“Since there is less UV in winter than in summer, it is true that wearing sunglasses is particularly important in summer. However, in winter, the sun is low and a person who is standing is oriented perpendicular to the rays of the sun, hence the interest of wearing sunglasses also in winter when the weather is nice“, replies our interlocutor. Summer or winter, beach or city, it is better to wear sunglasses, especially when the weather is nice.

Thanks to Pierre Cesarini, director of the Association Sécurité Solaire

Source: Sunglasses: how to choose the right protection? Directorate General for Competition, Consumer Affairs and Fraud Prevention / Afnor standard: Eye and face protection – Sunglasses and associated eyewear – Part 1: sunglasses for general use