Visual impairment

Visual impairment, also known as vision impairment or vision loss, is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses. Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses. Visual impairment is often defined as a best corrected visual acuity of worse than either 20/40 or 20/60. The term blindness is used for complete or nearly complete vision loss. Visual impairment may cause people difficulties with normal daily activities such as driving, reading, socializing, and walking.

The most common causes of visual impairment globally are uncorrected refractive errors (43%), cataracts (33%), and glaucoma (2%). Refractive errors include near sighted, far sighted, presbyopia, and astigmatism. Cataracts are the most common cause of blindness. Other disorders that may cause visual problems include age related macular degeneration, diabetic retinopathy, corneal clouding, childhood blindness, and a number of infections. Visual impairment can also be caused by problems in the brain due to stroke, prematurity, or trauma among others. These cases are known as cortical visual impairment. Screening for vision problems in children may improve future vision and educational achievement. Screening adults may also be beneficial. Diagnosis is by an eye exam.

Blindness (disambiguation)

Blindness is a visual condition.

Blindness may also refer to:

See also

Blindness (novel)

Blindness (Portuguese: Ensaio sobre a cegueira, meaning Essay on Blindness) is a novel by Portuguese author José Saramago. It is one of his most famous novels, along with The Gospel According to Jesus Christ and Baltasar and Blimunda.

Plot summary

Blindness is the story of an unexplained mass epidemic of blindness afflicting nearly everyone in an unnamed city, and the social breakdown that swiftly follows. The novel follows the misfortunes of a handful of characters who are among the first to be stricken and centers on "the doctor's wife," her husband, several of his patients, and assorted others, thrown together by chance. After lengthy and traumatic quarantine in an asylum, the group bands together in a family-like unit to survive by their wits and by the unexplained good fortune that the doctor’s wife has escaped the blindness. The sudden onset and unexplained origin and nature of the blindness cause widespread panic, and the social order rapidly unravels as the government attempts to contain the apparent contagion and keep order via increasingly repressive and inept measures.