Color Blindness

Color blindness is a form of visual impairment. Certainly it is not as severe an impairment as the types discussed elsewhere in this entry, but it is fairly common and does pose challenges to both students and teachers.

2% of women and 8% of men are in some way color blind. There are various types of the impairment – protanopia, deuteranopia, and tritanopia – but they are generally grouped together under the umbrella term, “color blindness.” These conditions are inherited and sex-linked because they exist on the X-chromosome. However, other factors besides genetics can also lead to color blindness, such as parental drug use, some types of contraceptives, and even maternal diet during pregnancy.

Color blindness is actually quite easy to test for, but it is very hard to detect in terms of identifying children who should be tested for suspicion of being colorblind. Because children are colorblind from birth, they do not know of their impairment to communicate it. Instead, they develop coping mechanisms to cover for those instances when their impairment affects them. Although testing is available as early as 3 years after birth, there is no state law requiring it and many children do not get tested early enough.

The consequences of undiagnosed colorblindness can be quite serious for a student. IN some cases, it may lead to being misdiagnosed as learning disabled. Consider the example posited by one writer:

"Tom" is typically an happy reader, but today he does not volunteer to read. His problem stems from the fact that the story is printed in blue with a purple background. "Tom" is unable to see the letters clearly and therefore, is unable to read with confidence. If a teacher is not educated in the area of colorblindness he or she may misdiagnose the problem, but if they are made aware of the possibility of color deficiencies, special measures can be taken to help students. Allowing "Tom" to read off of black and white copies of the story will help improve the contrast and allow him to read with confidence.

Some other ways that colorblindness can negatively affect students in our classrooms: Class texts that are printed in a variety of colors and with colorful graphics, colored maps, transparencies, colored counting beads, and green or brown chalkboards that do not provide as much contrast in colors. In all these instances, the information provided will be very difficult if not impossible for colorblind students to process and comprehend.

The article cited below also includes examples of how undetected colorblindness can have serious repercussions for students as they pursue certain careers. If their condition is not diagnosed, they may pursue careers that depend to some extent on the ability to discern colors. Some of the careers that are suggested as possibly color-dependent are “police, fire protection, electronics, military service, pilot training, medical training, fashion designer, cosmetology, biology, agriculture, decoration, and chemistry.”

Two examples are given of students who could not continue in their chosen profession after years of study and large capital investments: (1) a pre-med student was denied admission to medical school because he could not distinguish blood from tissue samples under a microscope, and (2) a police officer had a case dismissed because he misidentified the color of the getaway car.

Teachers can make minor adjustments in instructional strategies and materials to help colorblind student access material. These include labeling with words or symbols when the child needs color recognition, increasing the contrast by using white chalk on a black board, being aware of "trouble" areas, and by making black and white copies of colored text.

Although colorblindness does not impair learning or other life activities to the degree that "regular" visual impairment does, it is a less obvious disability that teachers should be aware of and sensitive to in order to serve all of our students.

Lilliston, Melanie. “Color Blindness and Testing in Children.” Perception. 2000. 2 August 2007. <>.

This page was created by Dan Gordon.