What's the difference between nearsightedness and farsightedness?
Nearsightedness and farsightedness are two very common — and very different — types of vision conditions. Both are refractive errors, or abnormalities of the eye that affect its ability to focus light on the retina.
The medical term for nearsightedness is myopia. This occurs when light entering the eye does not focus properly on the retina, the membrane that lines the back of the eyeball. Instead, the light falls short — usually because the eyeball has grown too long. As a result, distant objects appear blurry. Close-up vision, on the other hand, is not affected.
Farsightedness, or hyperopia, is somewhat the opposite of nearsightedness. It usually is caused by an eyeball that's too short, which causes light to come to a focus behind the retina instead of directly on it.
Typically, farsightedness makes close objects appear to be out of focus, while distant objects remain clear. But high amounts of hyperopia may cause objects at all distances to be blurry.
Mild cases of farsightedness might not affect vision at all but cause headaches when reading or doing other close work.
Interestingly, children usually are born farsighted. In most cases, this early childhood hyperopia decreases as the eyeball lengthens with normal growth and development.
Nearsightedness, however, usually develops during childhood, worsens during adolescence and stabilizes during young adulthood.
Nearsightedness and farsightedness share some common symptoms, including headaches, eye strain, squinting to see clearly, and eye fatigue.
Experiencing any of these symptoms is an indication that a comprehensive eye exam with an optometrist or ophthalmologist is needed to determine a diagnosis and treatment options.
Treatment for nearsightedness and farsightedness
Both nearsightedness and farsightedness can be treated with corrective eyeglasses and contact lenses. The lenses work by changing the way light rays bend into the eyes.
Many people find that their nearsightedness or farsightedness stabilizes once they’re in their twenties. When there is no more change in refractive error, LASIK and PRK are two surgical procedures that can permanently correct myopia or hyperopia by reshaping the cornea so light comes to a clear focus on the retina.
Page published on Thursday, January 23, 2020