When the sun shines, we reach for our sunglasses to protect our eyes against bright sunlight and harmful UV rays.
But glare protection is often confused with UV protection – even though they’re two completely different things. The amount of glare protection or depth of tint a lens has does not reveal how much UV protection the lens offers.
Not many people know that to prevent our eyes being damaged by UV light, it’s not only sunglasses that offer effective UV protection – clear lenses also get the job done. However, just because a pair of sunglasses has dark lenses, a tint or glare protection, doesn’t mean it offers excellent protection against UV radiation.
UV protection actually has little to do with depth of tint or glare protection. If your sunglass lenses feature a low-quality UV filter, wearing them can actually do more harm than good. That’s because dark lenses let less light through, causing the pupil to dilate. So if your sunglass lenses have low UV protection, it can actually damage the cornea, conjunctiva and ultimately the parts of the inner eye such as the lens and even the retina.
Besides glare protection, a good UV blocker is the most important feature of any sunglasses. Clear lenses should also have a UV filter in order to protect against radiation damage.
But there are major differences in quality when it comes to UV filters. There’s no standard kind of UV protection. Whether they’re clear or tinted, many lenses only protect the eyes against UV light up to a wavelength of 380 nm.
Different health bodies, such as the World Health Organization (WHO), recommend UV protection up to 400 nm.1 ZEISS lenses therefore automatically offer comprehensive UV protection up to 400 nm – that applies to clear, sunglass and tinted lenses.
While the CE mark on the inside of the frame temples indicates whether or not your sunglasses feature UV protection, it only guarantees protection against harmful UV rays up to 380 nm. A UV camera reveals what is invisible to the naked eye