What is Color Blindness?

by Aug 19, 2020

It is likely that at some past eye examination, you have been screened for color vision deficiencies. Often, this comes in the form of asking you to discriminate a number/ shape from a background of random colored dots. Color vision deficits can be something that you are born with or they can be acquired later on in life due to medications, injury, changes in the nerves at
the back of the eye, etc. Read on to learn about the reasons why our color vision sometimes does not function properly.

Why are Some People Color Blind?

At the back of the eye, there are special cells called rods and cones that absorb light and transmit signals to the brain. Rods are great for detecting faint lights, especially in the dark. Cones are responsible for detail and color vision and there are three different types for different colors: red, green, and blue. The varying degrees that these different cones respond to light
determine what color is perceived (i.e. red is perceived if the red cone responds and orange is perceived if the red cone responds along with slight response from the green cone). In color vision deficits, the complete lack of a type of cone or the decrease in number or response of a cone type will affect the color perceived.

Red Green Color Blindness

Patients with red green color blindness, otherwise known as protanopia/protanomalous color vision or deuteranopia/ deuteranomalous color vision, often confuse reds with greens. This can manifest in varying degrees from having slight difficulty telling them apart to being completely unable to differentiate them. Often, this type of color vision deficiency is genetic and the
individual will be born with it. Because of how the genetics work, it is often males that are affected while females are unaffected carriers of the responsible gene. Certain diseases can also cause an altered perception of these colors such as swelling of the optic nerve at the back of the eye.

Blue Yellow Color Deficiency

Blue yellow color vision defect is most often acquired later on in life due to chronic use of certain medications, cataracts, glaucoma, etc. Although it can also be genetic, it is much rarer than red/green color blindness. These patients experience difficulty discerning blues from yellows. Similar to red/ green color deficiency, the degree of difficulty can vary. Often, this may not be a concern. Depending on the degree of the color blindness, many peopleare not even aware of it until they are tested for it, though they may suspect it based on family history. There are certain occupations that require one to be tested for color vision deficits, such as pilots, police officers, military, etc. A color vision deficit may also affect career performance in areas where fine color discrimination is important, such as visual arts or interior design.


Our eye doctors at Wilmington Family Eye Care in Wilmington, DE excel in prescription of glasses, contact lenses and the diagnosis of a variety of eye diseases. Call our optometrists at 302-299-1286 or schedule an eye exam appointment online if you would like to learn more about color blindness and color deficiency. Our eye doctors, Drs. Daniel Baruffi, Joseph Goldberg, and Karen Darrell and Patricia Jones provide the highest quality optometry services and eye exams in Wilmington, Delaware and its surrounding areas.

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