Figure 21.32 Common Vision Disorders Animation Video
During normal vision, light travels into the eye and focuses directly on the retina, providing a clear image of whatever is being observed. In a person who has myopia, a common vision disorder known as nearsightedness, light is focused in front of the retina rather than directly on it. This is caused by an elongated eyeball shape. As a result, objects nearby are clear, but objects in the distance are blurry. In a person who has hyperopia, also known as farsightedness, light that enters the eye is focused beyond the retina rather than directly on it. This condition is caused by a shortened eyeball. The result of hyperopia is that objects in the distance are clear, but objects nearby are blurry. These are common eye defects that usually can be corrected with prescription lenses.
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