July 5, 2012

How About Those Over-The-Counter Readers?

By Lisa Brothers Arbisser, M.D.
Eye Surgeons Associates

The eye is capable of changing its refraction (the ability to bend light to focus an image). When light enters the eye, the crystalline lens behind the pupil is partially responsible for focusing light on the retina, the layer of nerve cells that does the seeing. The shape of this lens determines its power for focusing. The ciliary muscle inside the eye attaches to the lens and can alter its shape. Without conscious effort, when we look from far away to up close, this muscle contracts allowing the flexible lens to become more rounded and thereby more powerfully bend light rays focusing on near images. This process is called “accommodation.” As we age, the crystalline lens inevitably becomes stiffer and loses the flexibility to round up no matter how much muscular effort is exerted. This explains the growing need for readers or bifocals.

As you reach the approximate age of 40 years, you may find it difficult to focus up close. At first you compensate by holding things farther away or taking off your glasses if you are a little nearsighted. You may experience some difficulty changing focus from distance to near and then develop “eye strain” or mild headaches with prolonged accommodative effort. These are most likely your body’s normal signals that it’s time to get some readers. Naturally, a good eye exam, recommended by the American Academy of Ophthalmology, every two years over the age of 45 even in the absence of symptoms, should be done to rule out the presence of any eye disease. Assuming your eyes are healthy and you need no glasses for distance, how about those readers?

Reading glasses do nothing more than add focusing power to make up for your own lenses’ inability to continue to provide added power by rounding up. These glasses contain a “plus” lens which increases magnifying power most commonly from +1.00 diopters to +3.00. A diopter is a unit of measurement of the refractive power of the lens. The older you get, the more likely you will be most comfortable with the stronger reader. To choose the best one, you can take a newspaper to the store, be sure the print is clear at a comfortable reading distance then hold the print an equal distance farther away and closer to you. If you can focus within the range, the glasses will be right.

With the exception of children whose visual system is still developing, glasses only provide comfort and clarity. Research shows no permanent harm due to incorrect glasses, though they can cause considerable temporary discomfort. Over-the-counter readers will not be adequate for people with asymmetry between the two eyes or for those who require a glasses prescription for distance vision, but this will be evident as vision will not be clear.

Over-the-counter readers are not subject to the same quality control available from opticians and dispensing ophthalmologists and optometrists, but a study by the American Academy of Ophthalmology showed no harm done by these glasses. Many optometrists and ophthalmologists offices also carry affordable and trendy over the counter reading glasses and have staff to help you find the correct reading power.

So, if appropriate, keep a pair by the phone, your bed, or the desk so you won’t have to curse your age as often while looking for your glasses.

Cofounder of Eye Surgeons Associates Lisa Brothers Arbisser, MD, is board certified and specializes in cataract surgery. She sees patients in our Rock Island and Bettendorf offices. For more information please see our web site at www.esaeyecare.com.