Understanding UV Protection in Sunglasses
Not all sunglasses offer the same level of UV protection. When shopping for sunglasses, you'll often see terms like UV400 or UV380 — but what do they actually mean, and which one should you choose?
What Is UV Radiation?
Ultraviolet (UV) radiation is invisible light emitted by the sun. It's divided into three types:
- UVA — long-wave UV, penetrates deep into the eye and is linked to cataracts and macular degeneration
- UVB — medium-wave UV, causes sunburn and can damage the cornea
- UVC — short-wave UV, mostly absorbed by the Earth's atmosphere
What Does UV400 Mean?
UV400 sunglasses block all light rays with wavelengths up to 400 nanometres — covering 100% of UVA and UVB radiation. This is the gold standard for UV protection and is recommended by eye care professionals worldwide.
What Does UV380 Mean?
UV380 sunglasses block light up to 380 nanometres. While this covers most harmful UV rays, it leaves a small gap between 380nm and 400nm unprotected. Research suggests that light in this range can still cause eye damage over time.
UV400 vs UV380 — Which Is Better?
UV400 is the superior choice. The difference of 20 nanometres may seem small, but it represents a meaningful improvement in eye protection, particularly for people who spend a lot of time outdoors. Opticians and the World Health Organisation recommend UV400 as the minimum standard for protective eyewear.
Does a Darker Lens Mean More UV Protection?
No — this is one of the most common sunglasses myths. Lens darkness (tint) has nothing to do with UV protection. A light-tinted lens with UV400 coating offers far better protection than a very dark lens without it. Always check the UV rating, not just the colour of the lens.
Are Cheap Sunglasses Safe?
Not always. Very cheap sunglasses may claim UV protection without actually delivering it. Worse, dark lenses without UV coating cause your pupils to dilate, allowing more harmful UV rays into your eyes than if you wore no sunglasses at all. Always buy from reputable brands that clearly state UV400 protection.
Shop UV400 Sunglasses at Missandtrendy®
Every pair of sunglasses at Missandtrendy® features genuine UV400 protection, so you can be confident your eyes are fully protected. Browse our full collection of UV400 polarised sunglasses for men and women.
Once you know your UV protection, find the perfect frame for you with our guide on how to choose sunglasses for your face shape. Or if you're a driver, check out the best polarised sunglasses for driving in the UK.