What is Colour Blindness?

Colour blindness is a condition in which a person has trouble telling the difference between various shades of colour. Colour blindness does not mean that a person sees things in black and white. Generally, Optometrists and Doctors refer to the condition as

 ‘colour vision deficiency’.

Who is affected by colour vision deficiency?

Almost all colour vision problems are inherited, and present at birth. It is estimated that 1 in every 12 males, and 1 in every 200 females, are born with some form of colour vision deficiency.

In later life, some serious eye diseases, and certain medications can cause colour deficiencies to appear.

How is a colour vision deficiency inherited?

The ‘colour blindness gene’ is passed down through the mother’s side of the family. A colourblind male will have inherited the condition through his mother’s genes (although she will probably not be colourblind) whereas a colourblind female will have inherited the condition through a combination of her mother’s genes (probably not colourblind) and her fathers (who will be colourblind).

Who should be tested for colour vision deficiency? 

People who should have there colour vision checked include;

• All Boys
  
• Girls in whom colour vision is suspect
  
• Children with a family history of colour blindness (particularly from uncles and grandfathers)
  
• Adults considering occupations that require fine colour discrimination
  
• Adults considering occupations that have colour vision standards
  
• Adults who have developed eye disease, such as cataract or macula degeneration

Colour vision testing is a fairly simple process and can be carried out with little difficulty from the age of 3 years (the child doesn’t have to know the names of the colours).

What can be done about colour blindness?

Medically, there is no cure for hereditary colour blindness, because the body lacks a given sensor for detecting particular colours.

Colourblind people often look for other cues to determine colour. For example, if you couldn’t tell the difference between red and green at the traffic lights, you could still tell that the top light meant stop.

Other means of compensating for colour blindness have been developed, such as specially tinted glasses. There are even computer programs available to help colour blind people distinguish colours.

Paul Mcdonald