On a beach on Arcachon Bay or in the city, not all sunglasses are equal. Behind two tinted lenses lie very different levels of protection, and a dark tint does not necessarily mean well-protected eyes. To choose a pair that truly protects, two markers are all you need: the UV400 label and the lens category. Here is everything, explained simply.
UV400: the real measure of protection
The sun emits ultraviolet rays (UVA and UVB) which, over time, tire and damage the eyes. The UV400 label means the lens filters out all UV rays up to 400 nanometres, in other words 100% of UVA and UVB. It is the benchmark for complete protection.
An important point: lens colour has nothing to do with UV protection. A clear lens can filter 100% of UV, while a very dark, low-quality lens can let it through. Worse, a dark tint without a UV filter makes the pupil dilate and lets in even more harmful rays. The only real assurance is the UV400 marking.
Sunglass lens categories, from 0 to 4
The category indicates how much visible light the lens lets through, in other words its ability to filter glare. It ranges from 0 to 4:
- Category 0: very clear or lightly tinted lenses. Comfort and style, little protection against glare. For indoors or overcast skies.
- Category 1: low brightness. Suited to cloudy days.
- Category 2: medium brightness. A good compromise for spring and autumn.
- Category 3: strong brightness. The most versatile category, ideal for everyday wear, by the sea, in the mountains and for most activities in full sun.
- Category 4: extreme brightness (high mountains, glaciers). Very dark lenses, not allowed for driving.
Key takeaway: the category handles visual comfort in bright light, UV400 handles protection against the rays. The two are complementary, and you need both.
UV400 and category 3: the right everyday choice
For everyday use in France, on the coast as well as in town, the combination of UV400 and category 3 makes the most sense. You get total UV protection and comfortable light filtering in bright sunshine, without lenses so dark they get in the way when you step into the shade.
That is exactly what we fit to our glasses: every model in our collection comes with UV400 category 3 lenses.
Polarisation: what it is really for
Polarisation is a separate option from UV protection and category. A polarised lens filters horizontally reflected light, the kind that creates blinding glare on water, wet sand, the road or a car body. The result: less glare, sharper contrast and truer colours.
For water sports, driving or simply a day in full sun on the Bay, it makes a real difference. Our polarised lenses are bionylon lenses supplied by Divel Italia, a maker of bio-sourced lenses. We go into this material in detail in our article on bionylon lenses.
Choosing well, in practice
Before buying a pair of sunglasses, check these points:
- The UV400 or "100% UV" marking. This is non-negotiable.
- The right category for your use (3 for everyday wear and full sun).
- Polarisation if you often face water, the road or strong light.
- The optical quality of the lens, with no distortion, ideally compliant with ISO 12870.
- CE compliance, which certifies that European standards are met.
At OCENEO: serious protection and responsible material
Effective sun protection does not force you to choose between quality and commitment. Our glasses are handmade on Arcachon Bay from recycled neoprene wetsuits, and fitted with UV400 category 3 polarised bionylon lenses. The frame is responsible, the optics are serious.
Got an old wetsuit sleeping in the garage? We can turn it into a one-of-a-kind pair with Recycle my wetsuit. And to discover all our models, head to our collection.
Protecting your eyes starts with reading the right markers. UV400 for the rays, category 3 for the light, polarisation for comfort: with these three criteria, you can't go wrong.
