How to prevent red eye , while taking pictures? what causes it/?

Some cameras have built in red-eye flash. I think red-eye is caused by some type of lighting, i'm not really sure. I do know that the Casio Exilim Z-60 has the red-eye flash, which prevents it. Actually, red eye is caused by the light of the flash bouncing off of the capillaries of the pupil and reflecting red in the shot. One way to eliminate that is to put more space between the flash and the lens. This only really works if you have a seperate flash.

Post processing with almost any photo program works too. It's hard to prevent red-eye because it's related to the size of the camera and the close proximity of the lens and the flash.

An SLR with a flash mount that allows you to pivot the flash at an angle to use reflected light, but that's a drastic step if you just want a pocket digital camera...

My recommendation is to avoid using the red-eye reduction setting on your flash. People always assume the picture is done when they see the red-eye reduction flash go off so they turn away just as your camera is about to take the actual shot. Just take the shot with an auto flash setting and use your editing software to get red-eye out later.

Besides, red-eye reduction only reduces red-eye (not eliminates), so you'll still have to go back and edit anyway.