Q. Do people who are colorblind see everything in black and white?

"Colorblindness" is the common term used to describe color vision deficiency. The term is misleading, because total colorblindness that turns the world into shades of gray is rare.The most common type of colorblindness makes it difficult for people to discriminate between red and green. The next most common form of the deficiency affects the perception of blues and yellows. Those with blue-yellow blindness almost always have red-green blindness, too.Many people with colorblindness don't know they have it. For example, they are taught at an early age that grass is green. They look at lawns and see yellow grass. Subsequently, if you ask them what color the grass is, they will tell you it's green.Colorblindness affects about 10 percent of men, but only 1 percent of women. Most people with colorblindness inherited it. There is no treatment to correct inherited colorblindness. However, there are specially tinted eyeglasses that can help people with deficiencies to discriminate between colors.Another cause of colorblindness is simple aging, which gradually diminishes our ability to see colors.Diseases can affect your color vision, too. Usually, diseases affect the perception of blue and yellow. Some conditions that can cause colorblindness are diabetes, glaucoma, cataracts, macular degeneration, Alzheimer's disease, Parkinson's disease, leukemia and sickle cell anemia.Some drugs can alter color perception, too. These include drugs for heart problems, high blood pressure, rheumatoid arthritis, nervous disorders and psychological problems.Exposure to certain chemicals can cause colorblindness. These include carbon disulfide, fertilizers, styrene and mercury.The eye is like a camera. There's a lens in the front that focuses images on the retina in the back. The retina contains nerve cells that react to light and transmit information to your brain. If the cells responsible for color don't work properly, you suffer from colorblindness.If you think you are having a color-vision problem, see an eye doctor. You'll be asked to look at a book containing several multicolored dot patterns. If you have a color vision deficiency, you won't be able to pick out numbers and shapes from within the dot patterns.The Times News, Inc., and affiliates do not endorse or recommend any medical products, processes, or services or provide medical advice. The views of the author do not necessarily state or reflect those of the Times News. The article content is not intended as a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician, or other qualified health provider with any questions you may have regarding a medical condition.