- Eye Diseases and Conditions Slideshow Pictures
- Pink Eye Slideshow Pictures
- Eyes and Eye Conditions Quiz
- Patient Comments: Blindness - Causes
- Patient Comments: Blindness - Diagnosis
- Find a local Eye Doctor in your town
- Blindness facts
- What is blindness?
- What are the different types of blindness?
- What causes blindness?
- What are symptoms and signs of blindness?
- How is blindness diagnosed?
- What are treatments for blindness?
- What is the prognosis for blindness?
- When is one considered legally blind?
- Is blindness preventable?
Quick GuideCommon Eye Problems and Infections
What are symptoms and signs of blindness?
All people who are blind or have visual impairment have the common symptom of difficulty seeing. People with similar levels of visual loss may have very different responses to that symptom. If one is born blind, there is much less adjustment to a non-seeing world than there is for people who lose their vision late in life, where there may be limited ability to cope with that visual loss. Support systems available to individuals and their psychological makeup will also modify the symptom of lack of sight. People who lose their vision suddenly, rather than over a period of years, also can have more difficulty adjusting to their visual loss.
Associated symptoms, such a discomfort in the eyes, awareness of the eyes, foreign body sensation, and pain in the eyes or discharge from the eyes may be present or absent, depending on the underlying cause of the blindness.
A blind person may have no visible signs of any abnormalities when sitting in a chair and resting. However, when blindness is a result of infection of the cornea (the dome in front of the eye), the normally transparent cornea may become white, making it difficult to view the colored part of the eye. In blindness from cataract, the normally black pupil may appear white. Depending on the degree of blindness, the affected individual will exhibit signs of visual loss when attempting to ambulate. Some blind people have learned to look directly at the person they are speaking with, so it is not obvious they are blind.
How is blindness diagnosed?
Blindness is diagnosed by testing each eye individually and by measuring the visual acuity and the visual field, or peripheral vision. People may have blindness in one (unilateral blindness) or both eyes (bilateral blindness). Historical information regarding the blindness can be helpful in diagnosing the cause of blindness. Poor vision that is sudden in onset differs in potential causes than blindness that is progressive or chronic. Temporary blindness differs in cause from permanent blindness. The cause of blindness is made by a thorough examination by an ophthalmologist.