The "cheaters" on the drugstore rack may help you read the menu, but they're no substitute for a professional eye exam.
If you're over 40, reading glasses can be a necessity, and they serve double duty as a fashion accessory. Be-cause they are inexpensive and available in a wide variety of styles—and easily misplaced—you may buy them by the handful. Yet, you may be better off investing in a professional eye exam instead.
"If you think you have solved the problem on your own, you may delay or even avoid getting regular eye exams," says Dr. Eli Peli, professor of ophthalmology at Harvard Medical School. Dr. Peli notes that any vision change is cause to have your eyes examined.
How our eyes age
As we age, the lens in our eye loses some of its flexibility. As a result, it becomes harder to focus on close objects. Small print can seem blurred or even indecipherable. It may be more difficult to do close work like sewing or drawing. if you are nearsighted, you may have to take off your glasses to read the paper or the menu. Difficulty refocusing at close range is known as presbyopia, literally "elder vision."
But the lens isn't the only part of the eye that is aging. If you have presbyopia you're also at increasing risk for developing other, more serious conditions like cataracts, glaucoma, and macular degeneration. "You should be having regular exams to check for these conditions, in addition to having your vision tested," Dr. Peli says.
When over-the-counter readers are good enough
Off-the-rack readers are essentially two magnifying lenses mounted in an eyeglass frame. Just like prescription lenses, they afford varying degrees of magnification, or refraction, usually ranging from +1.00 to +3.50 diopters. "These glasses may be fine for people who need the same refraction in both eyes or who have vision in only one eye. I tell patients who are in these situations to go ahead and use them," Dr. Peli says.
Even if you're a good candidate for nonprescription lenses, it's a good idea to get professional advice on the power of lenses to choose. Although some states prohibit the sale of lenses with a refraction of over +3.50 diopters, it's possible—and may be legal—to order them online. "But it isn't a good idea to go to these higher values without getting advice," Dr. Peli says.
When you need prescription lenses
If you need a different correction for each eye, or if you have astigmatism—irregularities in the lens of your eye—prescription lenses are a better choice. Your eyes will be tested to determine the lenses best suited to compensate for the problems with your eyes' optics.
Prescription lenses are also preferable if you require correction for distance vision. In that case, bifocal or multifocal lenses are probably a better choice, if only for the convenience of managing a single pair of glasses. Although some people find that they have trouble with space perception when they first begin to wear bifocals or when they get a new prescription, their eyes and brain eventually adapt.
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