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Speaker 1: Welcome to brain Stuff from how Stuff Works dot com

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Speaker 1: where smart Happens. Hi, I'm Marshall Brain. If you were

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Speaker 1: to look at your eyes retina with a microscope, you

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Speaker 1: would find two kinds of cells. There are rod cells,

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Speaker 1: which can see black and white images, and there are

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Speaker 1: cone cells, which can see different colors. There are actually

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Speaker 1: three types of cone cells which are sensitive to three

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Speaker 1: different colors of light. Some people are born without any

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Speaker 1: working cone cells. These people are completely color blind. All

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Speaker 1: they can see our images in black and white, like

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Speaker 1: a black and white movie. This condition is very rare,

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Speaker 1: though much more common is a genetic problem that causes

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Speaker 1: red green color blindness. In this case, the cones that

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Speaker 1: detect the color green do not work properly, or the

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Speaker 1: cones that detect the color red do not work properly.

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Speaker 1: The colors red and green look very very similar, and

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Speaker 1: the colored purple looks bluish. Mostly white males are affected

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Speaker 1: by this condition. Women can also be affected by red

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Speaker 1: green color blindness, but this is less common because the

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Speaker 1: damaged gene is located on the X chromosome. Be sure

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