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- Pink Eye Slideshow Pictures
- Eyes and Eye Conditions Quiz
- Patient Comments: Blindness - Causes
- Patient Comments: Blindness - Diagnosis
- Patient Comments: Blindness - Legally Blind
- Find a local Eye Doctor in your town
- Blindness facts
- What is blindness?
- When is one considered legally blind?
- What are the different types of blindness?
- What causes blindness?
- What are risk factors for blindness?
- What are signs and symptoms of blindness?
- What specialists treat blindness?
- How do health-care professionals diagnose blindness?
- What are treatments for blindness?
- What is the prognosis for blindness?
- Is blindness preventable?
Quick GuideCommon Eye Problems and Infections
What are the different types of blindness?
Color blindness is the inability to perceive differences in various shades of colors, particularly green and red, that others can distinguish. It is most often inherited (genetic) and affects about 8% of males and under 1% of women. People who are color blind usually have normal vision otherwise and can function well visually. This is actually not true blindness.
Night blindness is a difficulty in seeing under situations of decreased illumination. It can be genetic or acquired. The majority of people who have night vision difficulties function well under normal lighting conditions; this is not a state of sightlessness.
Snow blindness is loss of vision after exposure of the eyes to large amounts of ultraviolet light. Snow blindness is usually temporary and is due to swelling of cells of the corneal surface. Even in the most severe of cases of snow blindness, the individual is still able to see shapes and movement.
People often say, "I am 'blind as a bat' without my glasses." All bat species have eyes, and most have excellent vision at night but not in daylight. More importantly, the term blindness means the inability to see despite wearing glasses. Anyone who has access to glasses and sees well with the glasses cannot be termed blind.