When buying a new pair of sunglasses, there’s more to consider than just the style — it’s also important to think about how well they will protect your eyes from UV damage. With different lens categories and levels of UV protection to choose from, it can sometimes be difficult to know which is the best sunglasses option for you — so we’ve put together this guide to help.

How can UV rays damage your eyes?

Sunlight contains many different types of light rays, including invisible, high-energy rays called ultraviolet (UV) rays. While small amounts of sunlight can be beneficial for your body, frequent exposure to UV rays can have a negative impact on your vision — especially if you aren’t protecting your eyes correctly.1 The two types of UV ray that could potentially cause the most damage to your eyes are UVA and UVB rays. 

Short-term overexposure to harmful UV rays can lead to photokeratitis — a type of sunburn to the outer layer of the cornea that can happen after spending too much time at high altitudes with limited sun protection (like during snowsports). Symptoms can include red, swollen eyes, although they are usually temporary and should clear up quickly. Without the proper care and protection, UV light can also have an impact on your eyes over time. For example, long-term exposure to UV rays could increase the risk of specific eye conditions such as cataracts, age-related macular degeneration (AMD), and some types of eyelid cancer.2

The good news is that you can give your eyes a better chance of staying healthier for longer by wearing a good-quality pair of sunglasses with UV protection.

What do the different sunglasses categories mean?

When buying sunglasses, you may notice that they come in a range of different categories. The category of a pair of sunglasses simply refers to how dark (or dense) the lenses are. These range from 0 to 4, with 0 being the lightest shade and 4 being the darkest: 

  • Category 0 — clear or very light lenses for fashion and indoor use
  • Category 1 — pale lenses for overcast days
  • Category 2 — moderate lenses for protection against glare
  • Category 3 — dark lenses for bright days (the most common category)
  • Category 4 — very dark lenses for intense sunshine (i.e. on mountains and glaciers)

Category 4 sunglasses are ideal for snowboarding or skiing activities, as they let in less than 8% of UV light. However, this category is not recommended for use while driving as the lens is too dark to see clearly. Only sunglasses with a filter category of 0-3 are considered safe for driving.

Do darker lenses mean better UV protection?

It’s important to remember that the darkness of your sunglasses lenses has nothing to do with UV protection — it only helps to reduce the brightness of light that reaches your eyes. You’ll still need to ensure that your sunglasses have certified UV protection in order to keep them safe from damage. 

What is UV400 protection in sunglasses?

Sunglasses with UV400 protection can filter out up to 99% of UVA and UVB rays. This is slightly higher than what British Standards require for eye protection, which makes them the best choice to ensure that your eyes are fully protected from sun damage.3

Do all sunglasses have UV400 protection?

While UV400 lenses might offer the best level of sun protection — not all sunglasses have them. It’s entirely possible to buy a pair of dark-tinted shades (category 3-4) that do not provide adequate UV protection. Fashion sunglasses, for instance, can look both safe and stylish, however they may not always protect your eyes from UV damage.

How to tell if a pair of sunglasses offers UV protection

You can tell whether sunglasses offer UV protection by checking if the frame features the CE or UV400 mark. The category for the lens shade (0-4) should also be marked on the frame, for example, ‘C3’ followed by ‘CE’. The CE mark shows that the sunglasses conform with the health, safety and environmental requirements of the EU, and therefore offer a good amount of UV protection for your eyes. 

If you’re ever unsure whether a pair of sunglasses you’re looking to buy, or already own, has adequate UV protection, our store team should be able to tell you. When buying sunglasses online, carefully check the product description to make sure they offer UV protection.

How to choose the right sun protection for your eyes

It’s important to protect your eyes as much as possible from harmful UV rays — even on cloudy and overcast days. Always have a pair of good quality sunglasses to hand, especially during months when the sun shines a little brighter. If you wear prescription glasses, you might consider adding a UV coating to your lenses so that your eyes are protected at all times. You can read our guide to UV protection for prescription glasses to find out more.

Protection for specific eye conditions

It’s important for everyone to protect their eyes from UV damage — but especially those with specific eye conditions. People with photophobia or glaucoma can experience a particular sensitivity to sunlight which can cause eye pain and discomfort, so it’s particularly important to wear UV protection to help manage these symptoms. You might even decide to add polarising lenses which can help to block out bright sunlight glare reflected from flat surfaces like water.

Prescription sunglasses for children

Children under 16 are at a higher risk of UV damage to their eyes because their pupils are larger and the structures of their eyes (such as the lens) are clearer — letting in up to 70% more light than adults.1 The simplest way to make sure your child’s eyes are protected against long-lasting sun damage while they’re enjoying time outside is with a pair of high-quality sunglasses.

Finding your perfect pair of sunglasses

From designer to own-brand — we have a pair of prescription sunglasses to suit everyone’s style and eyecare needs. Most of our frames are now available to buy online, and our handy tool lets you virtually try-on any pair to see how they suit you. Or you can just pop in store to have a look at the range in person.


1. Mead, MN (2008), “Benefits of sunlight: a bright spot for human health”, in Environ. Health Perspect. 2008;116(4):A160–A167. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290997/ [accessed 07/05/2020]

2. National Eye Institute, New Research Sheds Light on How UV Rays May Contribute to Cataract [online]. Available at:https://www.nei.nih.gov/about/news-and-events/news/new-research-sheds-light-how-uv-rays-may-contribute-cataract [accessed 07/05/2020]

3. British Standards Institution (2015), Eye and face protection. Sunglasses and related eyewear. Sunglasses for general use. BS EN ISO 12312-1:2013+A1:2015.

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