UV Light and Your Eyes: What Sunglasses Actually Need to Do

What UV exposure is associated with

• Cumulative lifetime UV exposure is associated with cataract formation.
• Growths on the eye surface such as pterygium are more common in high-sun, high-wind environments.
• Intense short exposure, such as sunlight reflected off snow or water, can cause photokeratitis, a painful temporary burn of the cornea.

Darkness is not protection

A dark tint makes your pupils dilate. If the lens does not block UV, dilated pupils let more ultraviolet light reach the inside of the eye than no sunglasses at all.

Look for a label stating UV400 or 100 percent UVA and UVB protection. That specification is what matters; price and tint depth are not proxies for it.

Practical choosing tips

• Wraparound or larger frames reduce light entering around the edges.
• Polarisation reduces glare from water and roads; it is a comfort feature, separate from UV blocking.
• Children accumulate exposure over more remaining years, so their sunglasses matter as much as adults'.
• A wide-brim hat meaningfully reduces overhead exposure alongside glasses.
• UV passes through cloud, so bright overcast days still count.

Where this fits

No supplement has evidence comparable to simply blocking UV. If you are budgeting attention for eye health, protective eyewear and regular exams are the highest-value items on the list.