When you live in a sunny country like Spain, sun protection is very important. We wear sunhats and high-factor sun creams to provide the best UV protection for our skin, but what about our eyes?

With sunglasses, it’s easy to think that the darker the lenses, the more UV protection they provide. As such, many opt for dark, cheap, stylish pairs, believing they will provide adequate protection from the sun. But just like suncreams, there are a range of UV protection ratings for sunglasses too.

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 do UV rays damage your eyes?

Sunlight is made up of a number of rays, the most harmful of these being UV rays. In small amounts, UV rays can be beneficial for absorbing vitamin D into the body. However frequent exposure can have a negative effect on your vision — especially if you aren’t protecting your eyes correctly.

UVB rays, in particular, can have a big impact on your eyes. These rays are absorbed by the front parts of the eye — the cornea and the lens — which control the entry of light into the eye and act as a filter to protect other parts of the eye from damage. Frequent and unprotected exposure to UVB rays can have a damaging effect on the cornea.

This can leave the eyes vulnerable to a range of conditions. For example, UV damage to the conjunctiva (the thin layer of tissue that covers the eye) can lead to the development of a pinguecula — a yellowish bump close to the edge of the cornea. Since frequent exposure to dust and wind are also known to trigger pingueculae, expats who spend their time by the coast are at a greater risk of these. UV light can also damage proteins in the lens, triggering harmful reactions that may be associated with cataracts.1

It’s therefore important to wear a good-quality pair of sunglasses to ensure you adequately protect your eyes from the sun.

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 marked with UV400 protection block between 99 and 100% of UV light from your eyes. They work to filter and block out light rays with wavelengths up to 400 nanometres, including both UVA and UVB rays. To ensure your eyes remain fully protected from damage, it’s important to wear sunglasses outdoors even on overcast and cloudy days, because UV rays can still penetrate through the cloud cover.

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.2 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 eye care needs. Our full range of sunglasses is available to browse and try-on online, or you can just pop in store to have a look at the range in person.

For more help choosing your perfect pair of glasses, visit our buyer’s guide or your local Specsavers store.

At Specsavers Opticas, we offer a fully comprehensive experience for British expats, providing the same quality service you’d expect in the UK.


  1. Linetsky M, Raghavan CT et al. “UVA light-excited kynurenines oxidize ascorbate and modify lens proteins through the formation of advanced glycation end products: implications for human lens ageing and cataract formation.” Journal of Biological Chemistry, May 2014.
  2. 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].