Understanding Vision Problems -- the Basics
What Are Vision Problems?
The eyes are your body's most highly developed sensory organs. In fact, a far larger part of the brain is dedicated to vision than to hearing, taste, touch, or smell combined! We tend to take eyesight for granted; yet when vision problems develop, most of us will do everything in our power to restore our eyesight back to normal.
The most common forms of vision impairment are errors of refraction -- the way light rays are focused inside the eye so images can be transmitted to the brain. Nearsightedness, farsightedness, and astigmatism are examples of refractive disorders and often occur when the eyes are otherwise healthy. Refractive errors are correctable usually with glasses, contact lenses, or refractive surgery, such as LASIK.
Other vision problems may be related to eye disease. Retinal detachment, macular degeneration, cataracts, and glaucoma are disorders of the functional eye and its processing units. These problems can lead to blurry or defective vision. The goals of treatment depend on the eye disease and may include restoring vision, halting vision loss, and preserving remaining eyesight.
Here are descriptions of common vision problems.
Nearsightedness and farsightedness have to do with the way the eye brings images into focus on the back of the eyeball, where 10 layers of delicate nerve tissue make up the retina. Images that do not focus on the retina will appear blurry. The further away images focus from the retina, the blurrier they appear.
Nearsightedness, or myopia, affects nearly 30% of the population. It is the result of images being focused in front of the retina rather than on it, so distant objects appear blurred. A nearsighted person whose eyesight has not been corrected holds a book closer to the eyes when reading and has to sit in the front of the classroom or movie theater to see clearly. The condition runs in families and affects men and women equally, usually appearing in childhood and stabilizing in the 20s.
Farsightedness, or hyperopia, is the opposite of nearsightedness. The hyperopic eye focuses images slightly behind the retina, making nearby objects appear blurry. Children may outgrow mild farsightedness as they mature and the eyeball reaches adult size. Did you know that the eye grows during childhood? The length of the eye (from front-to-back) elongates nearly one-third between birth and age five.