How Sun Exposure Speeds Up Cataracts — and How to Protect Your Eyes

Cataracts are the leading cause of vision loss worldwide. While they’re often seen as a natural part of aging, there’s a surprising culprit that can speed up their appearance—the sun. Spending long hours outdoors without proper eye protection can quietly damage your vision over time.

According to the World Health Organization (WHO), cataracts are responsible for more than 50% of blindness cases globally—a condition that could often be delayed or prevented with simple protective habits.

Fun Fact: Your eyes can get “sunburned,” too! The condition, called photokeratitis, is like a sunburn on your cornea—and it can happen after just a few hours of unprotected exposure.

To understand why sunlight can harm your vision, it helps to know what your eye’s lens does. The lens focuses light onto the retina and is made mostly of protein and water. Over time, those proteins can clump together, forming the cloudy patches known as cataracts.

Sunlight—especially ultraviolet (UV) radiation—can speed up that process:

• Oxidative stress: UV light creates free radicals, unstable molecules that damage cells and proteins in the lens.
• Protein damage: These free radicals cause lens proteins to lose their shape and transparency faster than normal aging would.
• Accelerated aging: Chronic sun exposure can trigger cataracts earlier—particularly a type called cortical cataract, which affects the edges of the lens.

Dr. Andrea Thau, past president of the American Optometric Association, notes that “UV exposure is cumulative. Every minute you’re outdoors without eye protection adds up over a lifetime.”

The sun doesn’t stop at cataracts—it can affect other parts of the eye, too.

• Pterygium: Sometimes called “surfer’s eye,” this growth of tissue on the cornea can cause redness, irritation, and even blurred vision.
• Retinal damage: Prolonged exposure to UV rays can damage the macula, the retina’s central area responsible for detailed vision, potentially leading to age-related macular degeneration (AMD).

Did you know? Snow, sand, and water can reflect up to 80% of UV rays, meaning your eyes are exposed from above and below. That’s why sunglasses are just as important at the beach—or on the slopes—as they are in summer.

Protecting your eyes from UV radiation isn’t complicated—and it’s not just for sunny days. Even cloudy skies let up to 90% of UV rays through!

Here are three simple, science-backed ways to protect your vision:

1. Choose the right sunglasses:
   Look for lenses labeled 100% UVA and UVB protection. The tint or price doesn’t matter—the certification does. Wraparound styles or larger frames offer even more coverage.
2. Add a wide-brimmed hat:
   A good hat can block up to 50% of UV rays that would otherwise reach your eyes. Bonus: it keeps your skin healthier, too.
3. Get regular eye exams:
   After age 40, make annual checkups a routine. Early detection of cataracts or other eye damage can make all the difference, especially if you have conditions like diabetes that increase risk.

“Think of sunglasses as sunscreen for your eyes,” says Dr. Rishi Singh, ophthalmologist at Cleveland Clinic. “It’s one of the easiest ways to protect your sight for decades to come.”

Caring for your eyes is one of the best investments you can make in your long-term health and quality of life. Whether you’re hiking, driving, or simply running errands, protecting your vision from the sun takes only seconds—but it pays off for years.

Keep your sunglasses handy, wear that hat proudly, and don’t skip your checkups. Your eyes will thank you every sunrise.