How important are sunglasses to overall eye health?

Wearing sunglasses can help protect from eye diseases related to UV light exposure.

Protecting your vision from harmful UV rays

It’s common knowledge that wearing sunglasses provides some protection against harmful ultraviolet (UV) rays that hit and cause damage to our eyes when we’re outside. But have you ever considered what the full impact of not wearing sunglasses can be on your overall vision health?

In addition to providing us with daylight and warmth, rays from the sun also contain UV radiation that is invisible to the human eye but carries more energy and can penetrate the skin more easily than visible light. After going through the skin, UV light can then damage the cells around your eye, which can increase your risk of developing various eye diseases, cancers and other conditions^1,2.

Wearing sunglasses is one of the easiest ways to protect your eyes from UV-related conditions since they block out and reflect potentially damaging UV light¹.

Eye conditions that can result from exposure to UV light

Some eye diseases are caused by short-term exposure to UV light while others have a slow progression and are caused by exposure over long periods of time^2,3. For this reason, people of all ages should wear sunglasses often to protect their eyes when they’re outdoors³.

Here are some of the common conditions related to UV exposure:

• Photokeratitis. Commonly referred to as snow blindness, photokeratitis is caused by intense short-term exposure to UV light from reflections off of snow, ice, sand or water^3,4. Some call this condition a “sunburn of the eye” and symptoms include extreme sensitivity to light, a gritty feeling like you have something in your eye, excessive tearing and redness⁴. Photokeratitis rarely causes permanent damage to the eye⁴.

• Growths around your eye like pterygium or pinguecula^3,4. Pinguecula is a yellow raised growth on the white of your eye that is harmless but can cause irritation and discomfort¹. Pterygium — also known as surfer’s eye — is a raised wedge-shaped growth that goes from the outer layer of the eye to the cornea that covers the iris and pupil and can cause irritation and visual distortions¹. These conditions are both associated with increased exposure to UV light, and you can decrease your risk of developing either of these conditions by wearing sunglasses¹.
  
• Cataracts. Cataracts are cloudy areas in the eye’s lens that can cause blurry, hazy or cloudy vision¹. These spots on the lens are associated with increased exposure to UV light that can damage the proteins in the lens, creating cataracts^1,2,3. Over time, they may require surgery if they become large and severely impact vision, but they can be prevented by wearing sunglasses while you’re outside^1,5.

• Eyelid skin cancer. When UV light penetrates the skin, it has the potential to damage the DNA in skin cells, which increases the likelihood of developing various cancers including basal cell carcinoma and squamous cell carcinoma¹. Sunglasses can help block and reflect UV light so it won’t hit the skin around your eye, which can reduce your risk for developing either of these skin cancers^1,2.
• Age-related macular degeneration (AMD). AMD results from the breakdown of the macula, which is responsible for central vision and seeing fine details^1,2. Some studies found that increased exposure to UV light increases the risk for developing AMD, so wearing sunglasses can help with prevention^1,2.

What should you look for when buying sunglasses?

When buying sunglasses, the most important thing you should look for is that they block out 99 to 100 per cent of UV-A and UV-B rays or have a UV400 protection rating^1,2,3,4. Lenses that wrap around your head to block light coming in on the top, sides and bottom not only protect your eyes but also the skin around them to prevent skin cancers, sunspots and wrinkles^1,2. Some contact lenses protect from UV light but don’t block the rays hitting the skin around your eyes¹.

UV light from the sun can cause significant damage to your eyes and surrounding skin. Wearing sunglasses is important not only for helping you see on a sunny day, but also for protecting your eye health and preventing some types of eye diseases.

Disclaimer: Always speak to your primary health care provider and/or eye care provider before making any changes to your lifestyle, activities or diet.

References

1. https://www.nei.nih.gov/about/news-and-events/news/protecting-your-eyes-suns-uv-light#:~:text=Prolonged%20exposure%20to%20UV%20rays,are%20linked%20to%20UV%20exposure.
2. https://health.clevelandclinic.org/do-sunglasses-protect-your-eyes
3. https://www.aao.org/eye-health/tips-prevention/sun
4. https://www.aoa.org/healthy-eyes/caring-for-your-eyes/uv-protection?sso=y
5. https://www.nia.nih.gov/health/vision-and-vision-loss/aging-and-your-eyes