September 17, 2014

The Science of Colorblindness

In an earlier blog, we discussed what it meant to be colorblind, how often it occurs and what misconceptions there are. Although there isn’t any eye care treatment for colorblindness, the science behind what causes it is very interesting and worthy of further explanation.

As light enters our eyes and stimulates the retina, we are given the gift of sight. The retina is composed of two types of cells, rods and cones. Rods help us to see in low light, while cones handle color and vision detail.

Every visible color is a different wavelength ranging between 400 to 700 nanometers. The cones contain a light sensitive pigment allowing us to see one of three wavelengths of light – red, green, and blue. Each cone has different “coding instructions” for these pigments, so when the instructions are wrong, we see the wrong pigment which results in a color deficiency. Trichromasy is when the cones are able to see all three colors and their mixtures. Dichromasy is when they only see two.

Dichromasy is broken down in to 3 categories, however one of them is extremely rare. Protanopia is referred to as a “red-weakness” meaning the photoreceptors cannot identify this color. In this case, blue would not be distinguishable from purple, colors with red in them shift more toward green and appear paler. Deuteranomaly is when a person cannot see green. So colors that have green in them are harder to distinguish from others. The third, and rarest form is tritanopia, which is the absence of blue. With this case, blue colors appear green and purple colors appear red.

People with color deficiencies can still work and perform daily tasks like everyone else without being affected by the inability to see certain colors. Jobs in similar fields to art or graphic design might be a bit more challenging, but can still be accomplished.

If you think you might have a color deficiency, try taking a colorblind test. If you would like more information about color deficiencies call us at 877-871-1684 to schedule an appointment with one of our eye care specialists in Los Angeles.



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