Night blindness refers to the inability of the eye to adapt to reduced illumination, therefore, leading to a complaint of not being able to see in the dark. Individuals suffering from night blindness not only see poorly at night but also require some time for their eyes to adjust from brightly lit areas to dim ones.
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Colour blindness, on the other hand refers to the difficulty in seeing differences between some of the colors that other people can easily distinguish. It is most often genetic in nature, but might also occur because of the eye nerve, or brain damage or due to exposure to certain chemicals.