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Colour Deficiency

 

Question: What is Colour Deficiency?

 

Answer: Colour Deficiency* occurs when a person’s ability to distinguish colours and shades is less than normal. The term “colour blind” is often used, but usually incorrectly. Only a very small number of people are completely unable to identify any colours. It is important to note that colour deficiency is more common in males than in females.

 

This condition is usually inherited, but can also result from certain diseases, trauma or as a side effect of certain medications. Colour deficiency occurs when a person partially or completely lacks one or more types of the three cones in the eye needed to see colour.

There are three types of colour deficiency. Two different types of red-green deficiency exist, while there is only one type of blue-yellow deficiency. The red-green deficiencies are by far the most common and result in the inability to distinguish between certain shades of red and green. A blue-yellow deficiency is rare and results in the person not being able to distinguish between shades of blue and yellow. In very rare cases, some people may not be able to detect any colours at all. This person would see all things in shades of black, white and grey.

 

It is recommended that every child be checked for colour deficiency by at least the age of five. It is important to detect this condition early, because colour coded learning materials are used extensively in grade school. In addition, having this condition may affect the career path of the individual. Distinguishing colour is an important aspect of some jobs, such as pilots, electricians, police officers, military personnel and others.

Anyone that suspects that they have a colour deficiency should have a comprehensive eye health examination preformed by their Doctor of Optometry. The Optometrist can include a test for colour vision, which typically involves the patient viewing a series of coloured designs. The designs have been created in such a way that a person with normal colour vision can see certain figures in the designs. A colour deficient person will not be able to distinguish the figures in the designs.

 

A comprehensive optometric eye health examination done by your Optometrist can determine the presence of amblyopia or lazy eye. The earlier this condition is diagnosed, the greater the chance for a complete recovery. Treatment may involve covering the good eye so the brain is forced to recognize the amblyopic eye. This method of treatment will develop more connections between the brain and the affected eye and improve the vision in the eye. It should be noted that corrective lenses might also be necessary.

 

The Canadian Association of Optometrists recommends the following comprehensive eye health examination guidelines:

• Birth to 5 years: Immediately, if parents sense a problem, otherwise by age 3 and again prior to entering school.
• School age children 6-19 years: Annually or every 2 years.
• Over 19 years of age: Every 2 years or sooner if recommended by your Optometrist.

 

* All content is provided for education and information, and is no substitute for the advice of your optometrist. This information is provided courtesy of the British Columbia Association of Optometrists (B.C.A.O.). The B.C.A.O. assumes no responsibility or liability arising from any errors or omissions or from the use of any information contained herein.