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.

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 is with a pair of high-quality sunglasses.

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UV protection for glasses

If you already have a good-quality pair of sunglasses, you might be wondering whether it’s really necessary for your prescription pair to have UV protection too. But it’s important to remember that UV risk can be still high on cloudy or overcast days when it’s not really practical to wear sunglasses. This is because UV light is invisible and can penetrate clouds and even materials like the glass of your car windscreen.

Adding a UV-protective treatment to your prescription glasses is one simple way to keep your eyes protected against UV damage. Even lenses without a UV treatment do a good job of blocking out most UVB rays, but still allow most UVA rays to pass through. So, particularly if you spend a lot of time outside or even driving, having a pair of prescription glasses with a UV filter will take away the worry around whether your eyes are fully protected.

What kinds of UV treatments are available for prescription lenses?

Sun tint and UV protection

Adding a full sun and UV tint to your prescription lenses not only gives your eyes protection against UV damage, but can also help to enhance your vision. Tinted lenses can relieve eye strain and soften harsh lights, helping you to see clearly in bright weather conditions.

Reactions lenses

If you regularly move between outside and inside, then Reactions lenses might be a good option for you. They offer 100% blockage of UVA and UVB rays and change colour depending on your lighting conditions – so they’re clear indoors but darken like sunglasses in sunlight, meaning you only need one pair of glasses to keep your eyes protected in all conditions.

Polarising lenses

If you’re affected by glare during the day or while daytime driving, then polarising lenses might be a good option for you. Polarising lenses offer 100% UV protection and reduce harsh light glare reflected from flat surfaces, such as water or the road.

UV protection for children’s glasses

Kids spend long days playing outdoors and their young eyes can be more vulnerable to UV damage than adults, so it’s important to keep them protected. Our UltraClear SuperClean UV lenses for children are also smudge and scratch-resistant — perfect for rough and tumble kids. Learn more about UV lens treatments for kids’ glasses here, or ask about them in-store.

Top tips for choosing the right UV protection

Damage caused by UV light adds up over time, but it’s never too early or late to start protecting your eyes. Here are some things to keep in mind: 

Prescription glasses with a UV treatment helps keep your eyes safe in cloudy weather, but it’s still worth having a good pair of sunglasses for brighter days 

Choose frames that offer good coverage of the eye and fit well

If you regularly change between outdoors and indoors, then glasses with Reactions lenses can save the trouble of having two pairs

You can still be stylish while staying protected against the sun. We have a range of prescription glasses and sunglasses to suit your individual style — from designer to more budget-friendly frames.

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.

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  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.