We need sunlight. Its life-giving rays promote our physical and mental health in many ways. However, too much exposure to the sun’s rays, especially UV, is harmful.
Most of us know UV rays damage skin, and we see the evidence mainly in the form of sunburn in the short term and wrinkles or skin cancer in the long term. But many people don’t realize that the sun also damages eyes. This damage also shows itself both in short and long term ways.
Before discussing that impact, let’s gain a better understanding of UV light.
What is UV Light?
UV light, a type of electromagnetic radiation (ER), comes mostly from the sun and is invisible to the human eye. ER transmits in different wavelengths and frequencies, and the range of these is called the ER spectrum. This spectrum has seven regions ordered by decreasing wavelength and increasing energy/frequency. UV light sits fifth on the ER spectrum and has three general sub-bands: UVA, UVB and UVC light.
UV harms because it causes ionization. Ionization affects the chemical properties of atoms, causing them to form or break chemical bonds in ways they would not otherwise. While useful in chemical processing, this process damages living tissue like skin and eyes.
Most of the UV light we come in contact is from the sun, but only about 10% of sunlight is actually UV light. Of that 10%, only ⅓ penetrates the atmosphere and reaches the ground at the equator.
The small portion of UV light reaching us damages unprotected skin and eyes. Damaging UV light is made up of 95% UVA light and 5% UVB light. No measurable UVC light reaches us because it is absorbed by the ozone.
Artificial UV Light
A number of artificial sources produce UV light. Those include tanning booths, black lights, curing lamps, halogen lights, fluorescent and incandescent lights, some lasers, LEDs and welding lamps.
Medical and dental industries use artificial UV for killing bacteria. It’s also used in industries like automotive, electronics and graphic arts to cure inks and resin. Pet owners use UV bulbs to give reptiles Vitamin D, and fluorescent bulbs are used as lighting sources in homes, offices and stores.
Exposure to artificial UV sources can cause severe eye damage. Temporary damage often heals within a couple of days. Permanent damage usually only occurs right away with severe exposure. Any exposure, however, adds to the cumulative impact of UV light on eyes.
What Effect Does UV Light Have On Eyes?
Both UVA and UVB light, whether artificial or natural, have short and long term negative effects on eye health and vision. The cornea and lens, which focus the light we see, absorb UVB light. UVA light passes through to the back part of the eye, to the macula, and can damage central vision.
Some people are even more at risk for eye damage from UV light than others. Those include individuals with certain eye diseases, some individuals who have had cataract surgery, and those who take photosensitizing drugs. Some studies show people with light irises are also at risk for increased damage.
Even without special circumstances, limiting exposure to UV light is a good idea for long-term eye health. UV exposure damages eyes over time. So every time you’re outside without adequate protection, you accumulate damage and increase risk.
Short term eye problems caused by UV exposure come on quickly and usually resolve themselves. Long term, and often permanent, damage happens gradually over a lifetime. For this reason…
“It’s important to start wearing proper eye protection at an early age to protect your eyes from years of ultraviolet exposure.” (Summer UV Safety)
Excessive exposure to large amounts of UV radiation over a short period of time can cause some inconvenient, uncomfortable, and painful eye problems. The two most common are photokeratitis and photoconjunctivitis.
Also referred to as a “sunburn of the eye,” “snow blindness” and “welder’s blindness,” photokeratitis is an inflammation of the cornea and is usually temporary, though painful.
Photokeratitis results from intense, short-term exposure to UVB rays, especially if eyes are not properly protected. High altitude conditions and very strong ground reflection (e.g. snow, water) can contribute to the severity. Thus, it is often seen after long hours at the beach or snow skiing.
Symptoms appear within eight to 24 hours of exposure. They include red eyes, a gritty feeling, extreme light sensitivity and excessive tearing. Photokeratitis can also result in temporary vision loss.
Photoconjunctivitis, also temporary and reversible, is an inflammation of the conjunctiva, the membrane lining eyelids and eye sockets. The condition causes significant discomfort but does not usually impact vision.
While conditions such as photokeratitis and photoconjunctivitis usually disappear as eyes heal, the exposure they represent contributes to the cumulative effect of UV light on eyes and vision.
Damage from unprotected exposure as children, teens and young adults often does not show up until later in life. The more unprotected exposure eyes have to UV rays, whether artificial or natural, the more increased risk of developing a host of eye and vision problems later in life. Unfortunately, these long-term problems are not temporary.
A few eye conditions — pterygium, pinguecula and climatic droplet keratopathy — due directly to UV exposure are not well known but worth noting. Each presents long-term issues and are generally associated with individuals living in areas with significant UV exposure or who are outdoors a great deal of the time.
More common long-term eye problems, also with links to a lifetime of unprotected exposure to UV rays, include macular degeneration, cataracts and skin cancer.
Macular Degeneration (MD)
MD occurs when part of the retina is damaged. Central vision is lost as is the ability to see fine details. Peripheral (side) vision is usually normal with MD. Unprotected exposure to UV rays increases the risk of developing MD.
“The worldwide prevalence rate of [Age Related] MD resulting in impairment and blindness is 8.7%, making it one of the most common causes of blindness in patients over 65. Studies have shown that many individuals with macular degeneration have had greater UV exposure over their lifetime” (Ultraviolet Protection).
UV rays, especially UVB rays, can also cause cataracts. Cataracts, a clouding of the eye’s lens, is the leading cause of blindness in the world.
“Every year some 16 million people in the world suffer from blindness due to a loss of transparency in the lens. WHO estimates suggest that up to 20 per cent of cataracts may be caused by overexposure to UV radiation and are therefore avoidable” (Ultraviolet Radiation).
Prolonged UV exposure also often leads to skin cancer in and around eyelids. Melanoma, the most frequent cancer involving eyes, sometimes requires surgical removal of the eyeball. Another type of cancer, basal cell carcinoma, happens on eyelids. According to the American Cancer Society…
“Most skin cancers are a direct result of exposure to the UV rays in sunlight. Both basal cell and squamous cell cancers (the most common types of skin cancer) tend to be found on sun-exposed parts of the body, and their occurrence is typically related to lifetime sun exposure. The risk of melanoma, a more serious but less common type of skin cancer, is also related to sun exposure, although perhaps not as strongly. Skin cancer has also been linked to exposure to some artificial sources of UV rays.”
Fortunately, there are a lot of affordable and readily available options for protecting eyes against UV light, whether natural or artificial.
How Do You Protect Eyes Against UV Light?
Protecting eyes against UV light requires quality eyewear, a bit of knowledge and some common sense. Combine these consistently to avert much of the long-term UV exposure that damages eyes.
Quality eyewear protects eyes against UV light. In fact, UV coating on eyewear acts like sunscreen for eyes, and pretty much any type of eyewear can have it. New technologies on the horizon also eliminate backside UV radiation coming from light reflected off backs of lenses.
Whether you wear sunglasses, safety glasses, Rx eyewear or even contacts, you can get UV protection to help prevent long-term damage to eyes.
Before detailing a bit on each of these types of eyewear, let’s dispel a myth regarding lens tints/shades. A common misconception says lenses need to be tinted to protect eyes from the sun. This is not true.
“Lens tint is sometimes confused with how dark the lenses are, and some people feel that the darker the lenses the more effective they are. Unfortunately this is a false assumption… it is not how dark or light the lenses are that determines their effectiveness in blocking these harmful uv rays, but rather the coatings applied to the lenses!” (How Important Is Lens Tint?)
Choosing the Best Lens Tint helps in many ways from optimizing performance to providing better visibility and increased eye comfort. However, lens tint is unnecessary for UV protection. Still, having a good pair of sunglasses with a tint that best suits your needs is one of the best ways to consistently protect against UV rays.
Sunglasses should block at least 99% of UVA and UVB rays. If they aren’t labeled as doing so, don’t buy them. Also, quality matters. Higher quality sunglasses more likely have lenses matched in color and free of distortion or imperfections, which means they’re more likely to be worn.
Most ANSI Z87.1-2010 safety eyewear comes with UV protection. If lenses are polycarbonate, they naturally protect eyes against UVA and UVB. Regardless, UV-protective safety lenses are marked with a “U” and a number indicating the level of UV protection.
Some situations call for special eyewear to protect against concentrated and high-level exposure to UV light (e.g. tanning beds, welding and lasers.) Standard UV lenses will not provide adequate protection in these situations. In addition, working near concentrated use of UV light also increases exposure, so wearing appropriate eyewear is also recommended in these cases.
Many prescription glasses come standard with a coating protecting eyes from UV rays, but don’t assume they do. Ask for it.
Some people find prescription sunglasses or transitions lenses to be essential. Remember, however, that shading helps with comfort and visibility, enhances performance and reduces fatigue, but don’t assume they have UV protection either.
Some contacts come with protection against UV rays, but not all. The ones that do help provide some protection at all times. They also give additional protection from UV rays making their way in the sides, top and bottom of eyewear.
There are two classes of UV-blocking contacts.
- FDA Class I — For high-exposure areas such as mountains and beaches. Block 90% of UVA rays and 99% of UVB rays.
- FDA Class II — General purpose contacts for everyday wear. Block 70% of UVA rays and 95% of UVB rays.
Contacts certainly provide terrific secondary protection, but they should not be the sole source of protection. Pairing them with sunglasses when outside is the best way to achieve comprehensive protection.
With knowledge about quality UV eyewear in hand, let’s add a few common sense tips to help ensure your eyes are as fully protected as possible against harmful UV rays.
- Wear UV eyewear consistently. Doing so goes a long way in preventing long-term damage. Having multiple pairs and especially eyewear that fits well and is comfortable is crucial.
- Keep in mind that UV rays also come in through the sides, top and bottom of eyewear. So if you’re outside a lot, wraparound sunglasses are a good idea.
- Adding a wide-brimmed hat provides even more protection for areas eyewear cannot protect from reflection.
Using common sense along with educating yourself about how UV damages eyes is crucial for long-term eye health. So is understanding risk factors increasing a person’s chances of UV damage.
Who’s Most at Risk?
While everyone is at risk for long-term eye and vision damage due to UV exposure, some people are more at risk. Ask the following questions to help determine your level of risk for developing UV-related eye and vision problems.
- Do you spend long hours in the sun?
- Have you had cataract surgery?
- Do you frequently use a sunlamp, bed or booth?
- Are you on any medications that increase sensitivity to the sun?
- Do you live in the mountains or a sunbelt?
- Does your occupation require frequent exposure to artificial UV light?
- Do you have a retinal disorder?
A Mistake to Ignore UV Exposure
Eyes need natural sunlight to help regulate many bodily functions that are vital and significantly impact overall health.
“Allow the eyes to be exposed to natural outdoor light… helps the brain work better” (Sunlight: Good for the Eyes as well as the Brain).
But we don’t need a lot of UV exposure to gain the necessary benefits. In fact, just 5-15 minutes of sun exposure a few times a week is enough, less in locations closer to the equator or for those with fair skin.
Even in wintertime and on cloudy days, risk for UV damage to eyes does not go away. After all, UV damage can occur all year long, and the sun’s UV rays still pasess through clouds.
Don’t ignore the warnings. Instead, purpose to Eliminate Excuses and keep your eyes healthy for a lifetime.