What Does UV400 Mean? How to Tell If Sunglasses Have UV Protection

The short answer to what UV400 means: UV400 is a label stating that a sunglass lens does not let through ultraviolet light up to 400 nanometres. This protection cannot be judged by how dark the lens is or its colour; it is shown by the label, the CE mark and, if needed, a measurement. In Antalya, where the sun is strong for most of the year, the first thing to check when choosing glasses is not the colour of the lens but this label.

What does UV400 mean?

UV400 is a protection label stating that the lens does not let through ultraviolet (UV) light up to a wavelength of 400 nanometres, which covers almost all UVA and UVB. The number 400 in its name is not a strength or quality score; it shows the wavelength the protection extends to, in nanometres (nm).

The label describes a feature of the lens, not of the frame. The UV filter can be within the lens material or in a layer on its surface, and it cannot be seen. So when two pairs of glasses sit side by side, you cannot tell by looking which one has UV400 protection.

What is ultraviolet (UV) light?

Ultraviolet light is radiation from the sun that the human eye cannot see, with a shorter wavelength than visible light. It is divided into three groups by wavelength:

The 400 nanometre limit on the UV400 label is the upper end of the UVA range. In other words, a lens with UV400 protection filters across the range that covers both types of ultraviolet light reaching the earth's surface.

What is the difference between UV400 and the CE mark?

The CE mark states that the glasses have been placed on the market as a protective product that meets the rules, while UV400 states that their ultraviolet protection extends to 400 nanometres. They are not the same thing; they complement each other.

In Türkiye and the European Union, non-prescription sunglasses count as personal protective equipment and carry the CE mark. The European and international standard for sunglasses is EN ISO 12312-1. This standard sets the ultraviolet limit at 380 nanometres. The UV400 label describes protection that goes beyond this, up to 400 nanometres. So the presence of the CE mark on glasses does not mean the UV400 label is there too; the two are checked separately.

The category number describes not UV protection but how much visible light the lens lets through. You can find which category is used in which setting in our article on sunglass filter categories.

Do all sunglasses have UV400 protection?

No, not all sunglasses have UV400 protection, and not every product with dark lenses counts as protective eyewear. Because the EN ISO 12312-1 standard sets the ultraviolet limit at 380 nanometres, glasses that meet the standard may not carry the UV400 label. UV400 is additional information by which the manufacturer states that it gives protection beyond this limit.

On the other hand, glasses sold as toys or accessories, with no CE mark and no UV information, are not protective equipment. The lenses of such products may simply be tinted. When deciding, look not at the appearance but at the information on the glasses and in their documents.

Do darker lenses give more UV protection?

No, the darkness of a lens does not show its UV protection. Darkness only reduces the visible light reaching the eye; the filter that blocks ultraviolet light is a separate feature and can even be colourless. So a light-coloured or even clear lens can have UV400 protection, while a very dark lens can have none.

The same applies to lens colour. Grey, brown and green lenses affect colour perception and contrast differently, but the lens colour does not determine UV protection. A mirror coating also reflects some of the light reaching the lens, but on its own it does not mean UV400. Our article on sunglass lens colours explains in detail what the colours do.

Where is the UV400 label on glasses?

The UV400 label usually appears on the swing tag, on the sticker on the lens or on the information leaflet that comes in the box; on some models it is also on the inside of the temple. How and where it is written varies by manufacturer, so you need to look not at one place but at all the glasses' documents.

When you pick up a pair of glasses, you can check in this order:

1. Read the sticker on the lens and the swing tag. The UV400 or UV protection label is usually here.
2. Look at the inside of the temple. The CE mark and, on most glasses, the filter category number right next to it are printed here.
3. Read the information leaflet that comes in the box. The standard complied with and the protection information are stated here.
4. If you cannot find UV information anywhere, ask the seller and ask to see the information in writing.

The sticker and the swing tag are thrown away once you start wearing the glasses. Keeping the information leaflet and the invoice makes it easier to remember the glasses' features later.

Are UV400 and polarised lenses the same thing?

No, UV400 and polarised lenses are separate features; having one does not mean having the other. UV400 filters ultraviolet light, which the eye cannot see. A polarised lens filters glare reflected off flat surfaces such as water, wet roads, snow and the bonnet of a car.

The two features can be found together in the same lens. If glare bothers you by the sea, on a boat or on long drives, a polarised lens reduces it, but you still need to look for the UV400 label separately. You can read how a polarised lens works, its limits with screens and a simple test in our article what are polarised sunglasses.

How can you tell if sunglasses have UV protection?

The UV protection of sunglasses is shown in three ways: the UV400 label, the CE mark and a check with a device that measures UV transmission. Judging by eye, or by the colour or darkness of the lens, tells you nothing about it.

1. Check the label: UV400 should be written on the glasses or in their documents.
2. Look for the CE mark: non-prescription sunglasses are personal protective equipment and carry this mark.
3. Ask for the documents: the information leaflet and the invoice show where the glasses came from.
4. Have them measured: UV protection can be checked with a UV transmission meter at an optician's store.

This check is particularly useful for glasses whose label has been lost, that were a gift or whose origin is unknown.

With glasses that have no label, whose origin is unclear or that are suspected of being fake, the real problem is not the appearance but the possibility that there is no UV filter. You can find the other signs that help you spot fake glasses in our article how to spot original sunglasses.

What else should you check on sunglasses besides UV400?

Besides UV400, check the filter category, whether the lens is polarised, the lens colour, the lens material and how much of the face the frame covers. Each of these features answers a different question, and none of them replaces UV protection.

Why does UV protection matter?

UV protection matters because long unprotected exposure to the sun is a risk for the eyes, and because ultraviolet light cannot be seen, its effect goes unnoticed at the time. Glare makes you squint, but ultraviolet light gives no warning at all.

In a sunny coastal region like Antalya, this is part of everyday life. Around Belek and Kadriye, on the beach and by the pool, water and sand reflect light, so light reaches the eye not only from above but also from below and the sides. If you spend most of the day outdoors, a lens with UV400 protection, a frame that fits your face and a wide-brimmed hat go together. Children spend a lot of time outdoors, so the same care applies to their glasses.

If you notice pain, redness, sensitivity to light or a change in your vision, see an ophthalmologist. Sunglasses are protective equipment; they are not used to treat complaints.