Does colour blindness rule out RAF career?
Q A teenager who was hoping to join the RAF came to see me recently. His parents were worried he might be colour blind. I confirmed he did indeed have red/green colour blindness with my Ishihara chart. Is there anything I should do to help him?
ABy far the commonest colour vision defect is an impaired discrimination between some shades of red and green. It has an X-linked inheritance so is much more frequent in males (8 per cent) than females (0.4 per cent).
The Ishihara test was designed to pick up severe red/green defects and it can miss more subtle defects. But its ease of use and portability has made it the most widely-used colour vision test.
Although normal colour vision is useful for a range of everyday tasks, such as driving a car, there are a number of occupations where minimum standards are set. These include civil and military pilots, certain ground crew, sailors, the fire service and electrical engineers. A useful listing of the various visual requirements for these and other occupations can be found at www. eyecare-information-service.org.uk/ site/eyecaretrust.htm
The RAF has a range of well-described visual standards applicable to flying and non-flying personnel including colour vision standards. The Ishihara test is used with good illumination. A pass on all plates is graded as CP2.
Failure to read all the plates correctly is classed as CP4, although further, more specific, tests can then be used. Even if someone is graded CP4 this does not rule out a career in the RAF. His colour vision will be tested when he is assessed by the RAF and a decision will be made by its medical board.
Dr Scott Fraser is
consultant ophthalmologist, Sunderland Eye Infirmary