Are You Color Blind? Here’s How To Tell.

Do you have trouble distinguishing between red and green? Do you confuse the colors blue and purple? Do many of the crayons in a box look the same? If you answered yes to any (or all) of these, you may be color blind.

Dr Dieck
William B. Dieck, MD, FAAO

Affecting approximately 1 in 12 men and 1 in 200 women, color blindness is the inability to distinguish the differences between certain colors. This condition results from an absence of color-sensitive pigment in the cone cells of the retina, the nerve layer at the back of the eye.

Most color vision problems are inherited and are present at birth, although some people become color blind as a result of diseases such as diabetes or multiple sclerosis, or they develop the condition over time as they age.

There are different levels of severity of color blindness

Almost half of all color blind people are unaware of their condition, while 60% of sufferers experience many problems in everyday life.

Most color blind people are able to see things as clearly as other people but they are unable to fully distinguish red, green or blue light. In extremely rare cases, some color blind people are unable to see any color at all (achromatopsia).

The most common form: red/green color blindness

Most color blind people suffer from this type of color blindness. The term red/green, however, does not mean people mix up red and green—it means that they see red and green as the same color, and they also mix up colors which have some red or green in them. For example, a red/green color blind person will confuse blue and purple because they can’t “see” the red element of the color purple.

Similar problems can arise across the whole color spectrum, affecting not reds and greens but oranges, browns, purples, pinks and greys as well. Even black can be confused as dark green or dark blue.

What does a color blind person see?

Most people with a moderate form of red/green color blindness will only be able to accurately identify 5 or so colored pencils from a standard box of 24 pencil crayons.

They may have:

  • deuteranopia (green color blindness)
  • protanopia (red color blindness)
  • tritanopia (blue-yellow color blindness).

color blind1

 color blind2

4 visual tests for color blindness

Typical color vision tests check for the most common types of color vision deficiencies. Here are 4 that you can try yourself!



If you have normal color vision, you see a 42.
Red color blind people see a 2.
Green color blind people see a 4.



If you have normal color vision, you see a 73.
If you are color blind, you do not see a number.



If you have normal color vision, you see a 74.
If you are red/green color blind, you see a 21.
If you are totally color blind, you do not see a number.



If you have normal color vision, you see a 26.
If you are red color blind, you see a 6.
f you’re only mildly red color blind, you also see a faint 2.
If you are green color blind, you see a 2.
you’re mildly green color blind, you also see a faint 6.

Treating color blindness

There is currently no treatment for inherited color blindness. Color filters or contact lenses can be used in some situations to enhance the brightness between some colors, but many color blind people find these actually confuse them further rather than help.

Wondering if you’re color blind? Come see us.

If you’re having trouble distinguishing certain colors and think you might be color blind, please call (914) 232-1919 to make an appointment with one of our Westchester Health eye specialists at Westchester Health. He/she will perform a thorough eye examination, get a detailed family history and determine if indeed you have some form of color blindness. Also, he/she may suggest some adjustments you could make in your lifestyle to feel more confident about your inability to see certain colors. Whenever, wherever you need us, we’re here for you.

By William B. Dieck, MD, FAAO, Director, Ophthalmology Division, Vice President, Westchester Healthmember of Westchester Health Physician Partners