Color Blindness: How It Works, Explained Simply

Video Transcript

Colour blindness is usually not blindness at all. Most people with it see colour, just not the same range of shades as everyone else. Colour vision starts with cone cells in the retina. There are three kinds, tuned mostly to red, green, and blue light. Your brain compares the signals from all three to work out every colour you see. In colour vision deficiency, one type of cone is either missing or shifted in sensitivity, so those comparisons overlap and certain colours become hard to tell apart. Red green deficiency is by far the most common form. Reds, greens, browns, and oranges can look similar. Blue yellow deficiency is much rarer. It is usually inherited, and carried on the X chromosome, which is why it affects far more men than women. It can also be acquired later from certain eye conditions or medications. Most people manage well, using position rather than colour on traffic lights, labelling things, and choosing colour-blind friendly settings in apps and charts. A simple test at an eye exam can identify it. Inherited colour vision deficiency does not currently have a cure, though some filters can help distinguish certain shades. It is worth knowing about, since a few careers require specific colour vision standards. This video is for general education only. It is not medical advice. Ask your eye doctor what's right for you.