Colour Blindness Test
This is a test for colour blindness or to use a better but less common term, colour vision deficiency. Most so-called “colour blind” individuals are not truly colour blind but instead have abnormal colour vision. They only have problems distinguishing certain colours and shades of the same colour. They do not see only in black and white. True inability to distinguish any colours is actually rare.
Interpreting the results
If you are unable to see the number 15 and 29 respectively, you suffer from faulty colour vision. There is no cause for concern if you are already a known sufferer from defective colour vision from previous testing. There is no cure for hereditary colour blindness. However, if you previously had normal colour vision but now have faulty colour vision, you should see your eye doctor for an eye examination.
Understanding More About Colour Blindness
It is estimated that eight percent of males and fewer than 1 percent (about 1 in 200) of females are colour deficient. Most people suffering from colour blindness are born with the condition. They inherit the condition from their parents as an ‘X-linked trait’. This means that the gene causing the condition is located on the X sex chromosome. Males have an X and a Y sex chromosome, while females have a pair of X sex chromosomes.
Genetically, this means
males are predominantly affected.
females are not predominantly affected but are carriers of the defective genes. Carriers carry the gene and can pass it on to half their sons. Half their daughters can be carriers. Carriers themselves are not affected by the defect.
if the father is colour blind, all his daughters will be female carriers of the defective genes. All his sons will be spared.
if the mother is colour blind, all her sons will be affected and all her daughters will be female carriers.
Green colour weakness or blindness is most common, followed by red colour weakness or blindness. It is important to remember that not all cases of colour blindness are congenital as there are some diseases acquired later in life, like diabetic eye disease, glaucoma, retinal or optic nerve disease which may disrupt colour vision.
The Importance Of Colour Vision Testing