Blindness

Blindness is to not see anything. Some people are called blind, even though they can see a little bit. This is because they cannot see clearly, but only see unfocused shapes or colors. 

In modern countries, few young people are blind. In all the world, blindness is mostly caused by malnutrition and diseases of old people, like cataracts and trachoma. People can become blind because of diseases or accidents, but sometimes people are born blind.

Legal blindness is defined as a level of visual acuity low enough to qualify for disability benefits and\or special accommodations. Legal blindness is also defined as being unable to be completely corrected by prescription glasses or contact lenses.

Some people are color blind, which means they can see, but cannot tell certain colors apart. 

When people are blind they use such things as the alphabet in braille and guide dogs to do every day life things.  In addition, they may wear sunglasses all the time to hide and \or protect their eyes.

Famous blind people have included Louis Braille, the inventor of the braille alphabet, Stevie Wonder, Ray Charles and Helen Keller.

References

 Book on the history of blindness 
 Royal National Institute for the Blind 
 Scottish Sensory Centre 
 Blind Net
 Guide Dogs for the Blind Association

Category:Disability
Category:Vision