It’s summer and everybody knows that you need to wear sunscreen to protect your skin, but what about your eyes? The labels on sunglasses usually promise protection from ultraviolet light and other kinds of natural radiation. It is important to know what kind of light you need to protect your eyes from and what type of light is not necessarily harmful. Long-term exposure to ultraviolet, or UV, radiation in sunlight is linked to cataracts and eye growths, including cancer. So look for sunglasses that block 99 percent or 100 percent of all UV light. Polarized lenses cut reflected glare, such as the sunlight that bounces off smooth surfaces like pavement, car windows, chromed surfaces or water. They can be particularly useful for driving and fishing. Polarization has nothing to do with UV light absorption, but many polarized lenses are now combined with a UV-blocking substance. Check the label to make sure the lenses provide maximum UV protection.
There are two different types of eyeglass lenses. The single vision all-purpose lens is designed to correct distance vision while the multifocal lens is designed to correct both distance vision and near vision, with the upper portion focused for distance vision and the bottom portion is used for up close activities such as reading. Multifocal lenses are used to correct presbyopia, the eye’s natural diminished ability to focus on near objects that comes with age. Bifocals have a correction for reading on the bottom half of the lens and another for seeing at a distance on the top. Trifocals offer three different lens corrections, distance, intermediate and near vision, in one set of glasses. Progressive lenses function like bifocals or trifocals but they have a smooth transition between distance and near focal areas instead visible dividing lines. Progressive lenses cause more distortion than other types of lenses, making them difficult to wear for some.
Did you know that protective coatings for eyeglasses can help you keep your eyes healthy? Anti-reflective coatings help to diminish reflections off the surface of glasses, thereby allowing others to make eye contact with you more effectively and improving your appearance. Coated lenses allow more light to pass through them, improving contrast sensitivity and visual acuity. Some of these coatings can be especially helpful for people who are bothered by glare from headlights and other lights while driving at night. Another type of coating helps to protect your eyes from the harmful radiation of ultraviolet light. This type of coating may not be needed on some types of plastic lenses, because they inherently block UV light. For those who prefer one set of glasses for inside and outdoors, photochromatic lenses are a good option. Photochromatic lenses have a tint that varies based on light exposure, with a darker tint in sunlight and lighter indoors.
More than 38 million Americans wear contact lenses, thin, clear disks of plastic that float on the surface of the eye. Contact lenses are used to correct the same conditions that eyeglasses do, including nearsightedness, farsightedness, astigmatism and the inability to see close up. Depending on your lifestyle, your motivation and the health of your eyes, contact lenses may provide a safe and effective alternative to eyeglasses when used with proper care and maintenance. Lenses that are not properly cleaned and disinfected increase the risk of eye infection. Any lens that is removed from the eye needs to be cleaned and disinfected before it is reinserted. Lenses that are old or not properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Because a lens can warp over time, and because your corneas can change shape, the fit and power of the contact lens should be re-evaluated by your ophthalmologist on a regular basis.
Eye injuries are the leading cause of blindness in children in the United States, with most of these injuries attributed to sports. Ninety percent of sports-related eye injuries can be avoided with the use of protective eyewear like safety glasses and eye guards. Ordinary prescription glasses, contact lenses and sunglasses do not protect against eye injuries so protective eyewear should be worn over them. Most youth sports leagues do not require the use of eye protection so parents and coaches should insist that children wear safety glasses or goggles whenever they play. Protective eyewear, which is made of ultra-strong polycarbonate, is 10 times more impact resistant than other plastics, and does not reduce vision. All children who play sports should use protective eyewear, not just those who wear eyeglasses or contact lenses. For children who do wear glasses or contacts, most protective eyewear can be made to match their prescriptions.
Trusted by thousands of listeners every week, T. Glenn Pait, M.D., began offering expert advice as the host of UAMS’ “Here’s to Your Health” program in 1996. Dr. Pait began working at UAMS in 1994 and has been practicing medicine for over 20 years.