Do Sunglasses Really Protect Your Eyes From The Sun? Here's What To Know

Though the sun feels good on your skin, the UV rays it emits are harmful, especially for the eyes. According to Johns Hopkins Medicine, long-term sun exposure can negatively impact every part of the eye, which can eventually decrease a person's vision. 

Columbia University Irving Medical Center explains that UV rays can lead to the development of cataracts, which make your sight blurry, and can increase a person's chances of cancerous eyelid tumors, including basal cell carcinoma, squamous cell carcinoma, and uveal melanoma. Exposure to UV rays can also lead to macular degeneration, where you lose your central vision.

While you can't apply SPF to your eyes as you do to your body, wearing the right sunglasses creates a similar layer of protection. Every pair is different, so you have to check the label or any stickers on the lenses to ensure they can shield your eyes from UV rays. While some sunglasses offer protection from the sun's rays, others don't offer any protection, and can actually be worse for your eyes in the long run. Wearing sunglasses is the key to preventing long-term problems with your eyes as long as you pick lenses that can protect you.

Sunglasses block out harmful UVA and UVB rays

When you're looking to pick out a new pair of sunglasses, it only makes sense that the darker the lenses are, the more protection they'll provide. Unfortunately, this isn't how it works. You should be looking for glasses that actively block out UV rays instead. This is the harmful radiation that comes from the sun which can penetrate your eyes and skin.

Nashville-based ophthalmologist and a clinical spokesperson for the American Academy of Ophthalmology Dr. Rebecca Taylor revealed to Time that it's best to opt for lenses that specify the percentage of UVA and UVB rays they block out: "The most important thing is that the sunglasses block 99 to 100% of UVA and UVB rays." 

The size of your sunglasses also matters. While you may prefer a specific style, the larger the lenses, the more protection they will provide, per Revant Optics. In fact, glasses that wrap around are the best option because they also shield the sides of the face so the UV rays can't reach your eyes. 

Wearing sunglasses without UV protection does more harm than good

Wearing sunglasses can actually increase your likelihood of developing eye diseases and cancers if they don't block UVA and UVB rays. It's better to not put on sunglasses at all if you're going to use a pair that doesn't have this necessary feature.

When sunglasses only have dark lenses with no UV protection, it makes your pupils dilate because they need to let in more light for you to be able to see. However, this action also creates a larger space for your eyes to absorb the harmful rays along with the sunshine, (via Columbia University Irving Medical Center). They lead wearers to feel like they're being protected from the sun when they're not, which in turn can make wearers spend more time in the sun and expose themselves to more damage, according to Safety Glasses USA.

A dark lens doesn't inherently mean that your glasses provide UV protection, so ensure that you look for glasses that specify that they do offer protection, per For Eyes. While lens color does make a difference in some areas, such as warding off the sun's glare, light colors can provide just as much UV protection as dark colors.