Ask the Doctors

Dear Doctor: About a year ago, when I turned 44, I started using reading glasses that I purchased at the drugstore. They seemed to work just fine. Now I need a stronger pair, and I wonder whether using them has weakened my eyes.

Dear Reader: We're happy to reassure you that using over-the-counter readers -- or any kind of corrective lenses, for that matter -- will not weaken or damage your eyesight. However, the fact that you find you need to move to a higher level of magnification does indicate that your vision is changing. And considering that many adults begin to experience changes to their ability to see clearly at close range after age 40, it's not all that surprising.

This change in close focus is known as presbyopia, which occurs when the lens within your eye gradually becomes less flexible. This is believed to be the result of age-related changes to the proteins within the natural lens in the eye, and to the tissues of the surrounding muscles that cause the lens to focus. The loss in flexibility to the natural lens results in blurred vision when doing close-focus activities such as reading.

While you could certainly opt to buy a new pair of drugstore reading glasses with a higher level of magnification, we recommend that you use this shift in vision as an opportunity to visit an eye care professional.

One-size-fits-all reading glasses are certainly affordable, and a quick trip to the store is more convenient than a medical appointment. But chances are the generic readers will not correct your eyesight to the highest level of accuracy. That's because, for most of us, the prescription in each eye is at least slightly different. Many individuals also have a small amount of astigmatism correction in their prescriptions as well. Wearing the wrong glasses can lead to headache and fatigue as your eyes strain to achieve optimal focus.

A comprehensive eye exam not only yields a corrective prescription tailored to your specific needs, it also includes several other tests to detect vision problems, assess eye health and screen for eye disease. For example, your eye care professional will use special drops to dilate your pupil and examine the important tissues at the back of the eye, including the retina, the macula and the optic nerve. A test of the pressure within the eye, known as tonometry, screens for glaucoma.

If you already wear glasses to correct farsightedness, you have the option of blending the two prescriptions in a pair of bifocals, trifocals or progressive lenses. A pair of multi-vision glasses for life on the go, and a pair of reading glasses for sustained close work, will give you the best of both worlds. If you prefer contact lenses, multifocal contacts correct near, intermediate and far vision.

Age-related changes to vision, once begun, will continue. However, these changes can occur so gradually that they may be difficult to notice. That's why it's important to schedule regular eye exams and safeguard your vision.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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