Ishihara Colour Vision Test

What is Colour Blindness?

Colour blindness is a disorder that not to have ability to distinguish the colours. Colour blindness is a highly prevalent disorder that usually seen in men. The most common type is the inability to distinguish green and red colours. In some rare cases cannot be distinguished of all colours and the world is concern only black and white. Colour blindness occurs in one of every 20 men and one in every 200 women. Many people cannot realize spontaneously that they are colour blind.

Ishihara Colour Vision Test:

You may have the possibility of being a colour blind if you cannot read the numbers in the above figure. With a colourful human eye can detect colour and can distinguish the colours with retina. When the retina has a problem with perception of colours some colours or all the colours will be seen in grey.

Sequences of number above left to right; 45-74-15-5

Causes of Colour Blindness:

The reason of colour blindness is not known exactly. However, colour blindness is known as a hereditary disease. A person with colour blindness is higher in families likely to be a colour blind. In some cases, colour blindness can occur due to nervous system disease. If it is inherited colour blindness there will not be vision loss.