Colour Blindness

What is it?

Colour blindness is the reduced ability to distinguish between certain colours. It is usually inherited and present from birth.

It is more common in men, affecting around one in 20. Far fewer women, around one in 200, are affected.

What happens?

There are several forms of colour blindness. By far the most common form is red/green colour blindness, which involves the confusion of red and green - and is passed on through a faulty colour vision gene on an X chromosome as a recessive disorder. This type affects about 1 in ten men and has two forms:

In one rare form of colour blindness blues and yellows cannot be distinguished, in another all colours are seen in black and white.

Vision itself is not affected, only the ability to distinguish between certain colours

Why does it happen?

To see colours properly, colour detecting vision cells, called cones, are needed in the retina of the eye. Three types of cone cell exist, each being sensitive to red, blue, or green light. If one or more of these types of cells is faulty then colour blindness results.

Sometimes colour blindness occurs because of diseases such as macular degeneration or from side effects of medicines.

Can I stop it?

Not if it's inherited. If it is due to underlying eye disorders or medication then sometimes it can be treated and stopped.

Should I see a doctor?

This is not necessary unless other eye problems, for example blurred vision, are occurring.

Treatments

No treatment is possible for the inherited forms of colour blindness but then treatment is not needed since the condition is harmless.