Dr. Kristen Robinson of Saugeen Shores Family Eye Care answers questions about Sun Protection
When can a person do to protect herself from sun exposure?
The best things a person can do to protect themselves from sun exposure is to always wear: sunglasses (labeled as having adequate UV 400 protection), a hat to keep the sun off your face, clothing to cover your skin sunscreen to protect your skin that isn't covered
It is also important to limit your time in direct sunlight during the hottest hours of the day, particularly when the UV index is high (which indicates how strong the UV light is in a certain area; the higher the UV index the greater the risk of exposure to UV rays).
Sunglasses need to be labeled as UV 400 to ensure you are receiving the appropriate amount of sun protection. Many products can be misleading and say things like "UV absorbent" or not say exactly how much of the UVA and UVB rays are being blocked. This is one of the distinguishing factors between "cheap" sunglasses and more expensive ones.
It is extremely important to protect yourself from harmful UV light if you work or play in the sun regularly. For example, construction workers, farmers, truck drivers, sports participants and spectators, police officers, skiers, life guards and beach goers. Also, people who are taking certain medications can be more sensitive to UV light and should be more diligent about proper UV protection. Some photosensitizing drugs include certain tranquilizers, diuretics, oral contraceptives, and antibiotics, as well as anti-diabetic and anti-hypertensive medications, and even artificial sweeteners. There have also been some studies that show that people who spend a lot of time in certain lighting environments may be more sensitive to damage caused by harmful UV light. For example, if you work in an environment which is brightly lit with fluorescent lights or you spend hours in front of a computer terminal.
Don't forget, overcast or hazy days also have UV. UV protection is available not only in sunglasses, but also in a coating for clear glasses as well (it doesn't have to change the colour of the eyeglass lens).
What exactly are “ultraviolet rays?”
Ultraviolet (UV) rays are a form of electromagnetic radiation. Radiation exists in a spectrum from very high energy radiation (like x-rays and gamma rays) to very low energy radiation (like radio waves). To put it in perspective, UV rays have more energy than visible light, but not as much as x-rays. High energy UV rays often have enough energy to damage an atom or molecule, making them a form of ionizing radiation. This type of radiation can damage the essential DNA in cells, which can lead to cancer.
Sunlight is the main source of UV rays, but it can also come from man-made sources (i.e. tanning beds, video display terminals, fluorescent lights, welding torches). UV rays make up only a small portion of the sun's rays, but they cause the most damage to skin and structures in the eye. UV rays don't have enough energy to penetrate deeply into the body which is why their main effect is on superficial structures. UVA and UVB are the primary harmful types of UV rays. UVB rays are slightly stronger than UVA rays and are the primary cause of sunburns (on the skin and on the cornea of the eye) and are thought to cause most skin cancers, where as UVA rays tend to be linked to long-term skin damage such as wrinkles on the skin and macular damage in the eye. UVC rays aren't discussed very often in relation to sun damage because even though they are the strongest UV rays, they react with the ozone and don't reach the ground in sunlight. However, UVC rays are present in welding torches and mercury lamps.
Are sunglasses an important part of a sun protection plan?
Yes! Sunglasses are a tremendously important part of a person's sun protection plan! The structures in your eye are very sensitive and can easily be damaged by UV rays. Wearing sunglasses protects not only the skin around your eyes and tissues on the surface of your eyes, but also the internal structures as well. We strongly recommend UV protection (sunglasses) for all of our patients, in order to prevent diseases such as cataracts, macular degeneration, eyelid skin cancers, pterygias, intraocular and conjunctival melanomas, and keratitis (corneal sunburn), to name a few. People often don't realize how many ocular diseases are a result of UV exposure, and that many of these diseases can impair vision over time as well.