COLOUR BLINDNESS TEST
INSTRUCTIONS FOR COLOUR BLIND TEST:
First of all, Please Make sure that you switch off all screen filters on your computer or mobile such as blue light filter or Night filter.
You will see an image composed of small dots.
Look for a number that is hidden in the pattern of dots. The number will be a single digit from 0 to 9.
Select the appropriate button to indicate what you see in each image.
WHAT IS ISHIHARA TEST?
The test consists of a number of coloured plates, called Ishihara plates, each of which contains a circle of dots appearing randomized in colour and size. Within the pattern are dots which form a number or shape clearly visible to those with normal colour vision, and invisible, or difficult to see, to those with a red-green colour vision defect.
Other plates are intentionally designed to reveal numbers only to those with a red/green colour vision deficiency, and be invisible to those with normal red/green colour vision.
WHAT IS COLOR BLINDNESS?
Color blindness (also called colour vision deficiency by vision scientists), is a condition in which the retinal cone cells respond to light differently than normal.
People with colour blindness can usually still see colours but have colour confusions or see certain pairs of colours so similarly that they cannot tell them apart
Approximately 1 in 12 men and 1 in 200 women have some degree of colour blindness. There are different types of colour blindness but the most common is known as “red-green colour blindness.”
EVERY DAY LIFE PROBLEMS BECAUSE OF COLOUR BLINDNESS
COLOR-NAME CONFUSIONPeople with colour blindness might find it difficult to “name” some of the colours they see. Greens, yellows, oranges, reds, and browns may appear similar especially in low light. It can also be difficult to tell the difference between blues and purples, or pinks and grays.
DIFFICULTY WITH TRAFFIC SIGNALSGreen lights may appear to be extremely pale or even white. Yellow and red lights may appear indistinguishable, especially at night. People with colour blindness may react up to 30% slower to colour coded information, which affects their ability to safely operate a motor vehicle.
IMPAIRED COLOR PERCEPTIONPeople with normal colour vision can see about 1 million distinct shades of colour. Those with colour blindness see only about 5% to 10% as many.
HEREDITARY FACTORSInherited red-green colour blindness affects 1 in 12 men. Only about 1 in 200 women have colour blindness, but almost 1 in 6 are carriers of the gene. Red-green colour blindness is an X-linked recessive trait. Fathers with colour blindness pass the gene down to their daughters, and the daughters have a 50% chance of passing it down to their sons.