There are those who are color blind and never knew it until later in life. Do you think you might be one of those? My brother did not know he was color blind until he went into the paint business.
Another name for color blind is defective color vision or color vision deficiency. Most people who are color blind are not aware that they have this problem because they do not know how other people see the world in regards to color. There are people, however, who know that they have this vision problem when they are small children after they have started kindergarten. One of the first lessons a child at this age learns at school among other things are the colors.
When diagnosis and measurement is needed, color vision is tested by special color plates used in the daylight. This performance was indicated in the book, The American Medical Association, encyclopedia of Medicine. Also stated in this book, true color blindness, known as monochromatic, is when the world is seen only in shades of black, white, and gray. This is extremely rare.
Most cases of color blindness are inherited. Sometimes it can be caused by an optic nerve disease or by an injury. The majority of people who are color blind are males. Women may carry this defect and pass it on to a baby boy. Some people with this problem, have a difficult time differentiating between certain colors but are able to recognize other colors. For example, this person may find it difficult to tell the difference between red and green, but know all of the other colors. There is a familiar case where an acquaintance of mine cannot differentiate between red and green. When asked, does he have trouble with signals, I suddenly realized he doesn’t have trouble because he knows that the red is on top and the green is on the bottom.
People who are color blind generally live normal lives. It can be a problem when a person with color vision deficiency is planning on an occupation and is not aware of this situation. For example, if they are planning on an occupation or career that depends on color, they should be aware of this problem. For example, color blind people should not go into the paint business.
According to the book, The American Medical Association, Encyclopedia of Medicine, the following occupations may be unsuitable for these people: train driver, airplane or marine pilot, electrician, jeweler, commercial artist, color photographer, the person who is severely color deficient can potentially be dangerous as an electrician. An example of this is when color-coded wires cannot be properly identified.
The good news is that people who are mildly colored blind will have little problems during their life time.
Source: The American Medical Association, Encyclopedia of Medicine
Personal experience with my brother who is mildly colored blind and is doing quite well in his paint business