Welcome to brain Stuff from how Stuff Works dot com where smart Happens. Hi, I'm Marshall Brain. If you were to look at your eyes retina with a microscope, you would find two kinds of cells. There are rod cells, which can see black and white images, and there are cone cells, which can see different colors. There are actually three types of cone cells which are sensitive to three different colors of light. Some people are born without any
working cone cells. These people are completely color blind. All they can see our images in black and white, like a black and white movie. This condition is very rare, though much more common is a genetic problem that causes red green color blindness. In this case, the cones that detect the color green do not work properly, or the cones that detect the color red do not work properly. The colors red and green look very very similar, and
the colored purple looks bluish. Mostly white males are affected by this condition. Women can also be affected by red green color blindness, but this is less common because the damaged gene is located on the X chromosome. Be sure to check out our new video podcast, Stuff from the Future. Join how Staff Work staff as we explore the most promising and perplexing possibilities of tomorrow. The hou stufforks iPhone app has arrived. Download it today on iTunes.