2024-10-16
Most people understand the importance of wearing sunscreen to protect their skin from ultraviolet radiation. Far fewer give the same consideration to their eyes, yet UV exposure is a significant risk factor for several serious eye conditions. If you wear contact lenses, choosing ones with built-in UV protection adds a valuable layer of defence that works from the moment you put your lenses in until the moment you take them out.
Understanding UV Radiation and Your Eyes
The sun emits three types of ultraviolet radiation: UVA, UVB, and UVC. While UVC is absorbed by the atmosphere and does not reach us, UVA and UVB both reach the surface of the earth and can damage the structures of the eye:
- UVA (315-400 nm): Penetrates deep into the eye, reaching the lens and retina. Associated with cataract development and macular degeneration over time.
- UVB (280-315 nm): Primarily affects the front of the eye, including the cornea and conjunctiva. Responsible for photokeratitis (corneal sunburn) and contributes to pterygium growth.
Cumulative UV exposure is the concern. Each day spent outdoors without protection adds to a lifetime total that influences your risk of developing UV-related eye conditions. This is especially relevant in Alberta, where high altitude, clear skies, and long summer days mean significant UV exposure throughout much of the year.
How UV-Blocking Contact Lenses Work
UV-blocking contact lenses contain a UV-absorbing monomer that is incorporated into the lens material during manufacturing. This is not a surface coating that can wear off; it is part of the lens itself. The UV-absorbing molecules capture UV photons before they reach the cornea, lens, and retina.
Contact lenses with UV protection are classified by the FDA into two categories:
| Classification | UVB Blocked | UVA Blocked |
|---|---|---|
| Class 1 (highest) | 99% or more | 90% or more |
| Class 2 | 95% or more | 50% or more |
Major brands like Acuvue from Johnson & Johnson offer Class 1 UV blocking in many of their daily and bi-weekly lenses. Alcon's Dailies Total1, another popular choice, includes UV protection as a standard feature. When discussing your contact lens options with your optometrist, asking about UV classification is a worthwhile conversation.
The Unique Advantage of Contact Lens UV Protection
The key benefit of UV-blocking contacts compared to sunglasses lies in coverage geometry. Sunglasses sit on the bridge of your nose, several centimetres away from your eyes. Even wraparound styles allow UV to enter from the top, bottom, and sides of the frame. Studies have shown that up to 45 percent of UV radiation reaching the eye comes from peripheral exposure around the edges of sunglasses.
Contact lenses, by contrast, sit directly on the cornea. They move with your eye, providing consistent coverage regardless of the angle of incoming light. This means UV protection from contact lenses covers the central cornea and the area of the pupil at all times, with no gaps for peripheral rays to sneak through.
UV-blocking contact lenses provide consistent, gap-free protection directly on the eye. But because they only cover the cornea and not the surrounding tissue, they complement sunglasses rather than replacing them.
Conditions Linked to UV Exposure
Understanding the conditions associated with UV exposure reinforces why protection matters:
Cataracts
The World Health Organization estimates that up to 20 percent of cataracts may be caused or worsened by UV exposure. Cataracts develop when proteins in the lens of the eye break down and clump together, causing clouding. UV radiation accelerates this protein degradation.
Macular Degeneration
Age-related macular degeneration (AMD) is the leading cause of vision loss in Canadians over 50. While genetics and smoking are primary risk factors, cumulative UV exposure, particularly UVA, is believed to contribute to retinal damage over time.
Pterygium
Often called "surfer's eye," a pterygium is a growth of tissue on the conjunctiva that can extend onto the cornea and affect vision. It is strongly associated with UV exposure and is more common in people who spend significant time outdoors without eye protection.
Photokeratitis
This is essentially a sunburn of the cornea, causing pain, tearing, redness, and temporary vision problems. It can occur after just a few hours of intense unprotected UV exposure, particularly around reflective surfaces like water, snow, or sand.
Who Benefits Most
While everyone benefits from UV protection, certain groups should pay particular attention:
- Children and teenagers: Young eyes transmit more UV to the retina than adult eyes. The lens of a child's eye is more transparent, allowing more UV to penetrate to the back of the eye.
- Outdoor workers: Anyone who spends prolonged hours outside, whether in construction, agriculture, landscaping, or recreation, accumulates UV exposure rapidly.
- People with light-coloured eyes: Less melanin in the iris means less natural UV filtering, making light eyes slightly more susceptible to UV damage.
- Post-cataract surgery patients: The natural lens of the eye provides some UV filtration. After cataract surgery, the artificial intraocular lens may or may not include UV blocking, depending on the type used.
- High-altitude residents: Here in Alberta, our elevation means higher baseline UV levels than coastal areas at the same latitude.
UV Contacts Are Not a Replacement for Sunglasses
This is the most important caveat. UV-blocking contact lenses protect the cornea and the area immediately behind the pupil, but they do not cover the conjunctiva, the eyelids, or the skin around the eyes. These areas are also vulnerable to UV damage. Sunglasses with full UV protection remain essential, even when wearing UV-blocking contacts.
Think of UV contact lenses as a base layer of protection and sunglasses as the outer layer. Together, they provide comprehensive coverage that neither can achieve alone. At Fantastic Glasses in Okotoks, we carry sunglasses from brands like Maui Jim, Ray-Ban, and Oakley that pair perfectly with UV-blocking contacts for complete eye protection.
Choosing UV-Blocking Contact Lenses
Not all contact lenses include UV protection, and it is not always highlighted on the packaging. When scheduling your next eye exam and contact lens fitting, specifically ask about UV-blocking options. Your optometrist can recommend lenses that suit your prescription, wearing schedule, and lifestyle while including this important protective feature.
Many UV-blocking lenses cost the same as their non-UV counterparts, so there is often no financial penalty for choosing the more protective option. Brands like Acuvue Oasys, Acuvue Moist, and Alcon Dailies Total1 all incorporate UV blocking at no additional cost compared to similar lenses without it.
A Complete Approach to Eye Protection
Protecting your eyes from UV damage is a lifelong commitment. UV-blocking contact lenses are one piece of a comprehensive strategy that also includes quality sunglasses, wide-brimmed hats, and avoiding prolonged direct sun exposure during peak UV hours. For your everyday eyeglasses, consider lenses with built-in UV coatings as well.
At Fantastic Glasses, we can help you build a complete eye protection plan. Whether you need UV-blocking contacts, prescription sunglasses, or everyday glasses with UV-protective coatings, our 3-for-1 deal from $199 makes it affordable to cover all your bases. Book your appointment today and take the first step toward better UV protection for your eyes.