Why should you wear sunglasses in winter?

07 December 2021

Author: Kate Green

wearing sunglasses in winter

Can UV rays be harmful even when it’s cold?


Sunglasses are a staple of most summer outfits, with many of us owning several pairs to suit every occasion possible. Even though the winter months aren’t as warm as summer, it doesn’t mean that the sun’s harmful UV rays suddenly go into hibernation. In fact, with the winter sun sitting lower in the sky than it does during in summer, the UV rays are actually more harmful due to the different angle. During winter, the rays are at their strongest between 10am and 3pm so if you’re heading out on a crisp wintery morning, make sure you pop some sunglasses on. Ideally, your sunglasses will be wraparound style to prevent any UV rays from sneaking past the glasses and entering your eyes. While 75% of people surveyed are worried about UV safety, less than a third of them actually regularly wear sunglasses.


UV rays are especially harmful if you’re out in a snowy area or by a large body of water. Snow reflects 80% of the sun’s rays straight back into your eyes, highlighting that the temperature of the area you’re in has nothing to do with the dangers that come with UV light. Further to this, the higher the altitude of your location, the more damaging the rays can be. In fact, UV radiation increases by 5% for every 1,000 feet above sea level.


What happens when your eyes are exposed to UV rays?


The sun emits ultraviolet (UV) radiation which can cause damage to parts of your eye such as your cornea and lens. We are all aware of how the sun affects our skin and we take steps to avoid getting sunburnt, like making sure we put on SPF on a sunny day. It’s just as important to understand why we should protect our eyes from the sun. Too much exposure to UV rays can cause cataracts and macular degeneration, as well as increasing your chances of skin cancer, as the skin around your eyes (like your eyelids) is particularly delicate.


Two eye conditions which also come with over-exposure to UV rays are pingueculae and pterygia. Again, wearing sunglasses reduces your risk of developing them. A pinguecula is a non-cancerous lump on the white part of your eye, the sclera. It is usually yellow in colour and is made from protein, calcium and fats, with its formation triggered by too much exposure to UV rays. Although a pinguecula usually doesn’t affect your vision, it can cause some discomfort and mild irritation, as well as potentially causing you issues on a cosmetic basis.


A pterygium can develop after beginning as a pinguecula and then growing larger, developing its own blood vessels. Because of this, it appears red or pink in colour, rather than the yellow shade of a pinguecula, and can cause more discomfort. This is because the size of it disrupts the distribution of tears across the surface of your eye, bringing on dry eyes while also appearing more noticeable in your eye.

Symptoms of a pinguecula include:

  • Redness
  • Dry eyes
  • Swelling around eyes
  • Burning or itching eyes
  • Blurry vision


You can read more about the impacts of pingueculae and pterygia on our blog here, but the most important thing to remember is that you can help keep them at bay by wearing sunglasses outside on bright days.


Cataracts are the world’s leading cause of blindness, noted by the World Health Organisation. Cataracts form when your eye’s natural lens becomes cloudy due to eye tissues breaking down and the proteins in there clumping together. This is a natural process that occurs with age – usually beginning in a person’s 60s and worsening as the years go by. However, you can exacerbate the condition with certain lifestyle factors such as smoking, excessive alcohol consumption, and overexposure to UV rays. It is thought that UVB rays bring on the formation of cataracts sooner than they otherwise would form.


Spending too much time in the sun is also suspected to lead to AMD (age-related macular degeneration). This is a condition whereby the central part of your retina (the back of your eye) begins to degenerate. The macula is in control of your central vision, colour vision and fine details, so any deterioration of it can make day to day tasks extremely difficult. Over 600,000 people in the UK suffer with AMD and its occurrence is genetic, as well as being impacted by your smoking, dietary and exercise habits. The level of your UV ray exposure also has an effect on the onset of AMD, and this is potentially more serious than the development of cataracts as it is not as easily treatable. You can read more about AMD on our website here, as well as discovering information on treatment options and diagnosis.


What type of sunglasses protect your eyes best?


Aside from protecting your eyes from UV damage, sunglasses can also prevent exposure to adverse weather conditions such as wind which is known to exacerbate dry eyes and cause issues with streaming eyes. Some people also suffer with glare from icy roads when combined with the low sun, making it difficult to see and focus on the road. The brightness that comes with such low sun during winter months can also cause vision-related headaches. However, wearing sunglasses helps to combat this, dimming the brightness and therefore mitigating some of the effects.


Not all sunglasses are made equal though, and they certainly don’t all have the same level of protection for your eyes. Within the EU, guidelines state that sunglasses need to block at least 99% of all UVA and UBV rays. If you see the familiar CE symbol on the inside of your sunglasses frames, it means they meet these requirements and are guaranteed to provide a higher level of protection. The colour of the lenses doesn’t mean anything in terms of the protection that they provide from the sun, but brown-toned lenses are best for enhancing contrast, so ideal for situations such as driving. Grey lenses are best suited for reducing light intensity, but this doesn’t necessarily mean they’re any better for your eyes.


Above all, you want your sunglasses to fit your face closely to minimise the amount of UV rays that can enter your eyes from around the sides or top of your glasses. Wraparound style glasses are best for this but generally, the bigger the lenses, the better they’ll be at keep out sunlight.

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