How do you test children?

In order to diagnose color blindness (achromasia) in children, tests can be used for examination from about the age of three years. However, the tests are not very different from those used for adults. A typical test is the Ishihara Color Chart.

It is used to test whether the children recognize a pattern or picture composed of different color dots. While the color saturations differ, the brightness remains identical to the background. Thus, the test is only dependent on color tones, but not on contrast differences. Instead of the usual patterns of numbers or letters used by adults, children can use animal motifs or other simple images. Depending on age and understanding of the task, children can use an anomaloscope to mix green and red tones to create a specific yellow tone, or use the Farnsworth test to determine a color sequence

Can glasses help?

In color blindness, the sensory cells on our retina that are responsible for the perception of colors (the cones) are not functional. There are different cones for different color perceptions. In most cases of color blindness, only two of the three types of cones are intact.

These disorders are mostly congenital disorders and are hereditary. Unfortunately, glasses cannot compensate for such changes in the retina. People with color blindness usually develop their own strategies to compensate for this deficit. For example, they orientate themselves at traffic lights by whether the upper, middle or lower light is on and can thus manage without having to recognize the color exactly.

Can color blindness be simulated?

It is quite possible to simulate color blindness. If one looks at the tests used to diagnose color blindness, it is noticeable that they all require the patient’s cooperation. It is therefore possible to perform a test in a way that would indicate color blindness.

For example, one could pretend that one cannot recognize patterns shown on the Ishihara tablets. However, there are boards that can expose such simulants. These are tables that show differences in color tones and brightness.

These tables must be recognized by healthy people and color-blind people alike. If somebody simulates and claims not to be able to recognize these patterns, this is noticeable. However, most people try to simulate that they do not show any color sense disorder and try to pass the test by memorizing the cards.