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Asked by Benarapter to Wil on 14 Mar 2017.
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Wilhelmiina Toivo answered on 14 Mar 2017:
It’s usually a problem with the eyes. Your eyes have three different types of cells for perceiving different colours, and when one or more of these cell types or their connections to the brain are faulty, it causes colour blindness. Scientists believe colour blindness is usually a condition caused by genetics, but sometimes you can get it as a result of an illness (such as diabetes, multiple sclerosis, or different eye diseases)
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Comments
Diana commented on :
most common form is red-green blindness caused in the eyes. normal humans and other primates have 3 types of photoreceptor cells in the retina. these send signals to the brain and are connected pairwise into 3system: dark light, red green and yellow blue. if there is a lack o 1 type of retinal cell [either re or green receptor] the red green system is absent or very weak. this form is more common in males, about 1/20 as the gene for the cell is on the x-chromosome. if male inherits defective gene from mother then colour blind/deficient. mother is not colour blind as she has gene on other x -chromosome, she is a ‘carrier’. daughter can only be colour blind if BOTH x have gene, i.e. father is colour blind and mother is carrier, chance are 1 in 20 squared =1/400. daughter is usually normal if x from mother ok or carrier if x form mother defective.
haemophilia is also like this – it is a recessive disease carried on x-chromosome
there are other forms of colur blindness some cause by problems in brain or nerve cells to brain, but they are much arare