Multiple: Vision Disorders
Multiple: Vision Disorders
Vision disorders are a group of diseases and disorders that affect the sense of sight. Some are caused by infections or allergies, like conjunctivitis, but most are caused by abnormalities in the structure of the eye or changes in the eye over time as a result of aging. Some diseases that affect the whole body, like diabetes, may eventually cause vision problems in addition to other symptoms.
Refractive errors are a type of vision disorder in which the person cannot see clearly because the eye cannot properly focus the light that enters the eye. Hyperopia (farsightedness), astigmatism, and myopia (nearsightedness) are types of refractive error. They develop when the lens of the eye is too strong or too weak for the length of the person's eyeball or when the cornea (the transparent front part of the eye) has an abnormal curvature. Strabismus is a vision disorder in which the eyes are not aligned because the muscles that control the movements of the eyes are weak and uncoordinated.
Cataracts and glaucoma are vision disorders associated with the aging process. A cataract is a yellowish or cloudy discoloration of the lens of the eye, while glaucoma can lead to permanent damage to the optic nerve and eventual blindness.
SEE ALSO Astigmatism; Cataracts; Conjunctivitis; Glaucoma; Hyperopia; Myopia; Strabismus