Eye health: Myths and facts

Did anyone ever tell you not to cross your eyes because they might stick? Is that true?

Learn the facts about this and other common eye health myths:

Myth: Reading in poor light will hurt your eyes.

Fact: Before the invention of electric light, most nighttime reading and other work was done by dim candlelight or gaslight. Reading in dim light today won't harm your eyes any more than it did your ancestors' eyes or any more than taking a photograph in dim light will damage a camera.

Myth: Using your eyes too much will 'wear them out.'

Fact: You wouldn't lose your sense of smell by using your nose too much or your hearing by using your ears too much. Your eyes were made for seeing. You won't lose your vision by using your eyes for their intended purpose.

Myth: Wearing eyeglasses that are too strong or have the wrong prescription will damage your eyes.

Fact: Eyeglasses change the light rays that your eyes receive. They do not change any part of the eye itself. Wearing glasses that are too strong or otherwise wrong for your eyes cannot harm your eyes — although it might result in a temporary headache. At worse, the glasses will fail to correct vision and make you uncomfortable because of blurriness. However, it will not result in damage to any part of your eye.

Myth: Wearing eyeglasses will weaken your eyes.

Fact: Eyeglasses worn to correct nearsightedness, farsightedness, astigmatism or presbyopia will not weaken your eyes any more than they will permanently solve these types of vision problems. Glasses are simply external optical aids that correct vision for people who suffer from refractive errors. Exceptions are glasses given to children with crossed eyes (strabismus) or lazy eye (amblyopia). These glasses are used temporarily to help straighten their eyes or improve vision. Not wearing such glasses in these instances may lead to permanently defective vision.

Myth: Crossing your eyes may make them permanently crossed.

Fact: Your eye muscles are meant to allow you to move your eyes in many different directions. Looking left, right, up or down will not force your eyes to stay permanently crossed. Crossed eyes result from disease, from an uncorrected refractive error, or from muscle or nerve damage, not from forcing your eyes into that position.

Myth: Having 20/20 vision means that your eyes are perfect.

Fact: The term "20/20" denotes a person with excellent central vision. However, they may have other types of vision, such as side vision, night vision or color vision, that might be imperfect. Some potentially blinding eye diseases, such as glaucoma or diabetic retinopathy, can take years to develop. During this time, they are harming parts of the inner eye, but the central vision can remain unaffected.

Jennifer Garvey, M.D., is an ophthalmologist in La Crosse and Sparta, Wisconsin.