The sun is essential for life, it makes trees grow, it warms our bodies and elevates our moods, however too much light from the sun can be harmful. The dangers of excessive sun exposure and associated ultraviolet radiation (UVR) are evident with threatening skin cancers, however its effect on the eye is equally relevant as it is to the rest of the body.
Ultraviolet radiation is part of the light spectrum and consists of UV A, UV B and UV C with a wavelength of 10nm to 400nm. UVC rays are the highest-energy UV rays and potentially could be the most harmful to your eyes and skin. Fortunately, the ozone layer blocks virtually all UVC rays but the depletion of the ozone layer could allow high-energy UVC rays to reach the earth's surface and cause even more serious UV-related health problems, than currently exists from UV A and UV B alone.
The effect of UVR on the eye can include damage to your retina, leading to blurred or distorted central vision(macular degeneration), non-cancerous growths on the surface of the eye (pingueculae and pterygia), cataract development and even cancer of the eye and eyelids. Most UV-related eye problems occur very gradually after many years of repeated UV exposure but it's also possible to get painful sunburn of the eyes (photokeratitis) from just a few hours in bright sunlight.
It is therefore important to protect our eyes against the adverse effects of UVR. Sunglasses offer the greatest protection against UV rays, however not all sunglasses are equal. In order to offer the best protection, sunglasses need to have 100% UV protection or a UV 400 coating, Frames ideally should have a close fitting, wraparound design to limit the amount of light entering the eye from above and the side of the lenses. This together with larger lenses for coverage of the delicate skin around the eyes, offer the ideal sun protection. Wide brim hats are also an excellent supplement for adequate UV protection.
While UVR is predominantly found outdoors, they can also be emitted from artificial sources. Protective eyewear is therefore necessary indoors when engaging in activities that involve welding machines, tanning beds and lasers to name a few. The eye protection necessary is similar to that of sunglasses however the lenses do not have to be tinted.
Contact lens wearer or those interested in wearing contact lenses can enjoy an added measure of protection. Contact lenses with a UV-blocking feature are available. These contact lenses should not be worn in place of your sunglasses, but they do provide excellent added protection by blocking much of the UVR that can seep in from the top, bottom and sides of your sunglasses as well as offering additional protection indoors.
In addition to the protective measures mentioned above the following factors are important to consider; the time of day you choose to spend outside is important. The high-risk periods in the UV Index are between 10 a.m. and 4 p.m. It is estimated that at midday, UVR can be 10 times higher than three hours earlier or later. Protective eyewear should always be worn when outdoors even on a cloudy day as UVR can still be emitted. Opt to find a shaded area but note that while a shaded area is preferable to direct sunlight, UVR can still reach you as it can be reflected of surfaces such as sand, concrete and buildings.
The importance of sun protective eyewear in children
As mentioned, the risk of damage to our eyes from UV radiation is cumulative, meaning the danger continues to grow as we spend time in the sun throughout our lifetime. In fact, some experts say that because children tend to spend significantly more time outdoors than most adults, up to half of a person's lifetime exposure to UVR can occur by age 18. Children are also more susceptible to eye damage from UVR because the lens inside a child's eye is clearer than an adult lens and they have larger pupils enabling more UVR to penetrate deep into the eye. Children who spend a lot of time outdoors receive three times the annual UVR dose as adults. Therefore, adhere to the sun protection tips and make sure your children’s eyes are protected with good quality sunglasses and encourage them to wear a wide brim hat when they go outdoors.