The harmful effects of the sun’s ultraviolet rays have been well documented. However, one of the most important, but often overlooked, areas of concern is the damage prolonged exposure to the sun can cause your eyes.
A recent report from The Vision Council estimates nearly 35% of the adult population have experienced eye or vision damage resulting from prolonged exposure to the sun’s ultraviolet rays.
To shed light on the importance of protecting the eyes from ultraviolet rays, it’s important to understand the various types of ultraviolet rays, the serious eye conditions that can occur, and how to protect your eyes and your vision from damage caused by exposure to the sun.
Key differences between ultraviolet rays
Before discussing eye issues the sun can cause or contribute to, it’s helpful to take a look at the specific types of ultraviolet rays emitted by the sun. Ultraviolet rays, more commonly known as UV rays, are a type of radiation produced by the sun and are the leading cause of skin cancer. There are three specific types of UV rays:
- UV-A is the most prevalent type of ultraviolet ray, accounting for over 95% of the UV rays reaching the earth. UV-A rays are the least intense of the three UV rays, but they are also the UV ray that penetrates the deepest into the eyes.
When exposed in excess, UV-A rays have been shown to affect the inner layers of the eye, including the retina (which is responsible for converting light signals into neural signals that are sent to the brain for visual recognition).
- UV-B rays are the most intense of the UV rays and are primarily responsible for affecting the surface level of the skin (epidermis) and the outermost layer of the eyes.
UV-B rays typically affect the cornea (the clear outer covering of the eye that is responsible for letting light into the eye). Eye damage caused by UV-B often includes sensitivity to light, eye irritation, and excess tearing.
- UV-C is the most damaging UV ray to both the skin and eyes. Fortunately, nearly all natural UV-C rays coming from the sun’s rays are blocked by the ozone layer. Typically, the only way someone is exposed to UV-C rays is through a man-made source, like a laser.
Serious eye conditions caused by exposure to the sun
Photokeratitis is literally a sunburn occurring on the cornea of the eye. Also commonly referred to as snow blindness, welder’s flash, or a flash burn, photokeratitis is an inflammatory response occurring in the eyes after the damage is caused by UV-B light.
Characterized by pain or redness in the eyes, watery eyes, sensitivity to light, and swelling, symptoms of photokeratitis typically appear six to eight hours after prolonged exposure to direct sunlight. In more severe cases, symptoms of photokeratitis might also include eyelid twitching, the sensation of grit or sand in the eyes, halos, color changes in vision, and even temporary loss of vision.
There also appears to be a direct correlation between the severity of symptoms and the length of time the eyes are exposed to UV light.
While most cases of photokeratitis are temporary, lasting between eight and 24 hours, long-term or repeated exposure to UV rays has been shown to increase the risk of developing more serious eye conditions, including cataracts and macular degeneration.
Pinguecula and pterygium
Pinguecula and pterygium are types of growths that occur on the conjunctiva, or the clear covering of the sclera (the white part of your eye), as a result of exposure to UV light.
Pinguecula is typically characterized by a small, white, or yellowish bump that grows only on the conjunctiva of the eye. It commonly contains tiny amounts of fat, protein, or calcium. Most people experiencing this condition typically live in areas that are very sunny and are also dry, sandy, and/or dusty.
Because it only occurs on the conjunctiva, a pinguecula typically does not interfere with vision. However, in severe cases, it can cause an issue with how tears are released into the eye and can result in irritation, redness, and dry eye. In these cases, the irritation or discomfort is often treated with prescription strength eye drops provided by your eye doctor.
A pterygium, or “surfer’s eye,” is similar to a pinguecula in that it originates and grows on the conjunctiva. However, unlike a pinguecula, a pterygium has more of a wedge shape and can extend onto the cornea. When the growth extends onto the cornea, it’s very common to experience irritation and distorted vision.
In severe cases where vision is being impacted and left untreated, a pterygium can result in scar tissue forming on the cornea—a condition that may contribute to permanent vision loss. Should this occur, surgery might be required as a way to preserve vision. While surgery is often successful in removing a pterygium, it’s important to point out there is a high rate of recurrence with this condition.
Repeated or long-term exposure to damaging UV rays has also been associated with an increased risk of developing macular degeneration.
While researchers and doctors do not yet have a full understanding of the relationship between sun exposure and macular degeneration, there is evidence to suggest that the sun’s ultraviolet rays appear to contribute to age-related macular degeneration.
Doctors suspect when the macula, or center of the retina, is repeatedly subjected to damage caused by UV radiation, it begins to change. As the macula changes, it’s common to experience blurry vision and blind spots, both of which increase in severity as the condition progresses.
Repeated exposure to UV rays has also been shown to cause—or accelerate—the development of cataracts. Research conducted by the National Eye Institute has demonstrated frequent exposure to sunlight causes something known as oxidative stress in the lens of the eye.
Over time, oxidative stress causes the tiny proteins found within the lens of the eye to clump together, which has been found to contribute to the clouding of vision and the development of cataracts.
Is sun damage treatable?
While your eyes are very resilient and able to recover from various injuries and conditions, damage caused by the sun is often difficult to treat or repair and, in many cases, permanent.
While conditions like cataracts are treatable through surgery, others like macular degeneration and the scarring caused by pterygium are often considered untreatable and cause damage that cannot be repaired.
Considering this, the most effective treatment for the damaging effects of UV rays is to prevent damage before it becomes permanent.
How to protect your eyes from the sun
While it’s nearly impossible to totally avoid exposing your eyes to the sun’s damaging UV rays, there are several things that you can do to minimize your risk, including:
- Making a point to always wear UV-protective sunglasses when outside, including fall, winter, and spring seasons
- Staying out of direct sunlight during the sun’s peak hours of intensity
- Wearing a hat with a brim that is wide enough to provide shade for your eyes
- Avoiding facing directly into the sun whenever possible
- Talking to your doctor about prescription sunglasses or transition lenses to ensure the best protection for your vision
Additionally, make sure you are scheduling regular checkups with your eye doctor to ensure your eyes are healthy and your vision is as clear as possible.