Many do not realize that they suffer from color blindness, especially in children. To ensure abnormalities in vision, can be done by doing a color blind test.  Color blindness is one of the vision problems. People who are color blind cannot see some colors clearly and accurately. They may find it difficult to distinguish between several colors, for example red-green, red-yellow-green, or blue-yellow, known as partial color blindness. Even in some people, absolutely not able to recognize color or total color blindness.  Main Causes of Color Blindness   In general, color blindness is caused due to genetic inheritance from parents who experience it. However, sometimes color blindness can also be caused by various factors other than genetic, such as:  Physical injury or chemical exposure  Optical nerve damage  There is a malfunction of the part of the brain that processes color information  Having cataracts  The aging process in old age   Color blindness can also be caused by a disease, ...