Ultraviolet Light Protection and the Health of the Human Eye

UV can have effects on the health of the eye similar to its effects on the skin.

By James W. Vann, OD

Ultraviolet (UV) light can affect the health of the eye in myriad ways that patients and eye care providers may not fully appreciate. An analogy I use with my patients is that, in the same way that too much sun exposure can result in wrinkled and aged skin, so too does UV light accelerate the aging processes that cause problems inside the eye. For example, cataract progression can be accelerated by UV exposure,1 and the most common melanoma above the neck affects skin around the eyes.1 Corneal degeneration can also be affected by UV light,1 and eye care practitioners well know that macular degeneration is affected by sun exposure.2

The internal structures of the eye are 10 times more sensitive to sun damage than the skin, and children may be at greatest risk. Studies have suggested that as much as 80% of damage to the eye from sunlight can occur by the age of 20, as the UV transmission of the crystalline lens decreases greatly with age.3

The cornea and lens filter some UV light, but the human eye still needs help with protection. Unfortunately, almost half of the population does not wear sunglasses. Even those who do wear sunglasses often wear them only on sunny days; however, UV light exposure is still dangerous on cloudy and overcast days.

These data paint a picture of potentially dangerous exposure that can have negative consequences for patients’ vision. What they also suggest is that eye care providers have tremendous opportunities to educate patients and discuss prevention strategies that can help them literally save their vision.

EDUCATION AND PREVENTION

I discuss UV light and its impact on the health of the eyes with every patient. It does not take much effort to initiate the conversation, and it can be included as part of the routine examination. For instance, if patients express concern about the appearance of the skin around their eyes, this can be an entry point to discussing eye health. Or, I might point to the macula on the optomap (Optos) imaging that we routinely perform and relate its importance to the patient’s visual ability; in that context, for an older patient, I might explain that losing even a small amount of function in the macula will result in not being able to see their children or other wonders of the world around them. But, I also explain that there are ways patients can protect that part of their eyes by being aware of sun exposure.

In addition to suggesting sunglass use for all patients, in my practice, we prescribe Transitions photochromic lenses (Transitions Optical) for all patients who use spectacles. I believe the technology in Transitions lenses is far superior to photochromic lenses in the past, and it offers great routine UV protection. For patients desiring something that is higher performing, better protecting, and polarized at all times, we prescribe sunglasses.

An added advantage of photochromic lenses is that they offer protection for the eye’s capability for dark adaptation. When light strikes the photoreceptors in the back of the eye, it causes a release of rhodopsin, which sends an electrical signal to the brain for processing. Too much light exposure exhausts the natural rhodopsin reserve; for every 15 minutes spent in bright sunlight, it takes up to 2 hours for the retinal reserve of rhodopsin to recover. UV protection is therefore not simply beneficial for visual performance; it is also key to preserving visual efficiency. Protecting against too much UV light exposure helps the eye to function as it should when it needs to adapt to changing light conditions.

 

ROLE OF DIET

When we discuss UV protection with patients, we always mention the role of diet. There is good evidence that eating foods that increase the pigment density, such as fruits and vegetables rich in carotenoids, helps to protect against macular deterioration and improves visual acuity in the process.4 We also recommend every patient use a supplement to add to their dietary intake, which follows from a recommendation established by the American Medical Association in 1999.5

In our office, we also use a device called the BioPhotonic Scanner S3 (Pharmanex/NuSkin) to measure the carotenoid antioxidant levels in patients’ skin. This device uses light to excite certain molecules in the skin so that they can be quantified with a spectrometer. We use this tool to measure for 15 carotenoid molecules in all patients so that we can give them a sense of their levels and what they mean for protection.6 Having a number to show the patient is valuable for encouraging compliance with diet modification and use of supplements.

FINAL THOUGHTS

I am surprised that more eye care professionals do not take the time to educate patients about the need to protect the eyes against UV light while they have them in the examination room. In our practice, we have made this a routine part of interacting with patients, and we have found tremendous success in educating patients about prevention.

Some manufacturers of contact lenses purport to offer UV protection in their lens platforms, but this is somewhat limited at the present time. In the future there may be contact lens technologies that offer full UV protection, but, for now, the only way to ensure robust protection for the eyes-and for the skin around the eyes- is to regularly use sunglasses. Transitions photochromic lens technology and polarized sunglass lenses are the best protective solutions.

These lens technologies, along with discussion of diet and supplementation, are all parts of a comprehensive approach to eye protection from UV light. n

1. Taylor HR. Ultraviolet radiation and the eye: an epidemiologic study. Trans Am Ophthalmol Soc. 1989;87:802-853.

2. Bodenham DC. Malignant melanoma of the head and neck. Excerpta Medica. 1975:85-91.

3. Sample PA, Esterson FD, Weinreb RN, Boynton RM. The aging lens: in vivo assessment of light absorption in 84 human eyes. Invest Ophthalmol Vis Sci. 1988;29(8):1306-1311.

4. Snodderly DM. Evidence for protection against age-related macular degeneration by carotenoids and antioxidant vitamins. Am J Clin Nutr. 1995;62(6 Suppl):1448S-1461S.

5. Fairfield KM, Fletcher RH. Vitamins for chronic disease prevention in adults: scientific review. JAMA 2002; 287:3116-3126.

6. NuSkin. Reference list. https://www.nuskin.com/content/nuskin/en_US/products/pharmanex/scanner/s3_studies_ref.html. Accessed June 13, 2016.

James W. Vann, OD
• VisionArts Eyecare Center, Fulton, Missouri
• (573) 642-6800; drv@visionartseyecare.com
• Financial interest: none acknowledged