Are You Color Blind? One in Twelve Men Are

Most “color blind” people aren’t completely color blind. People who are totally color blind can only see in black and white or shades of gray. They have a condition is called achromatopsia.

The rest of the people who are called “color blind”, should be more correctly called “color vision deficient”, which refers to the inability to distinguish between certain shades of color, usually shades of red and greens, but sometimes blues and yellows.

While people with normal vision can distinguish about 100 color hues, someone with color vision deficiency may only see 20. According to the American Optometric Association (AOA), “very few people are completely color blind.”

How Do You See in Color?

Inside your eye’s retina are photoreceptors known as cones. The cones contain light-sensitive pigments that allow you to recognize color. Your eye’s cone recognizes red, green, and blue light based on light wavelengths.

AOA continues - “Normally, the pigments inside the cones register differing colors and send that information through the optic nerve to the brain enabling you to distinguish countless shades of color.

But if the cones lack one or more light sensitive pigments, you will be unable to see one or more of the three primary colors thereby causing a deficiency in your color perception.

The most common form of color deficiency is red-green. This does not mean that people with this deficiency cannot see these colors at all; they simply have a harder time differentiating between them.

The difficulty they have in correctly identifying them depends on how dark or light the colors are.

Another form of color deficiency is blue-yellow. This is a rarer and more severe form of color vision loss than red-green since persons with blue-yellow deficiency frequently have red-green blindness too. In both cases, it is common for people with color vision deficiency to see neutral or gray areas where a particular color should appear.”

What Causes Color Vision Deficiency?

This condition is often inherited, passed from mother, who is typically a carrier of the gene but not color blind herself, to her son, in which case it will occur in both eyes. Color vision deficiency caused by injury or illness, which is less common, may impact just one eye.

Health conditions that may lead to color deficiency include:

1. Diabetes
2. Glacoma
3. Macular Degeneration
4. Alzheimer’s Disease
5. Parkinson’s Disease
6. Multiple Sclerosis
7. Chronic Alcoholism
8. Leukemia
9. Sickle cell Anemia

Aging can also affect your ability to see colors vividly, as can certain medications, including those used to treat heart problems, high blood pressure, infections, nervous disorders and psychological conditions.
Blue-green colorblindness is also a known side effect of the erectile dysfunction drug Viagra. Exposure to certain chemicals, such as styrene and fertilizers, may also cause a loss of color vision.

Men Tend to Have a Harder Time Distinguishing Among Different Shades of Colors:

It’s known that men and women tend to perceive colors differently, and one group of researchers suggested this could be due to the large number of testosterone receptors in the brain’s cerebral cortex.

Upon testing large groups of young adults with normal vision, they indeed found “marked sex differences in color vision.” Men, on average, were not as able as women to distinguish between shades of blues, greens, and yellows.

They concluded:

“We hypothesize that testosterone plays a major role, somehow leading to different connectivities for males and females: color appearance requires a re-combination and re-weighting of neuronal inputs from the LGN [thalamic neurons] to the cortex, which, as we show, depends on the sex of the participant.”

Do You Have Color Vision Deficiency? Take This Test to Find Out:

The Farnsworth-Munsell 100 hue test is one of the most well-known color blindness and color vision deficiency tests available. It involves sorting color plates by shade, which requires you to differentiate between colors and slight hue variations.

It consists of 88 color plates arranged in four batches of 22. They’re to be arranged so the colors appear to change gradually in steps.

By clicking this link, you can take this test for free online.

If your color vision is normal, you’ll probably get a perfect score or make just a few errors. Those with color vision deficiency will have increasing numbers of errors depending on the severity of the deficiency.

It’s not a perfectly reliable way to diagnose color vision deficiency, especially given the variations that can occur due to computer monitor settings and ambient light conditions. However, it can give you an indication of where your color vision stands. If you have any doubts, visit an eye doctor to have your vision screened.

Are You Giving Your Eyes the Right Nutrients?

Certain nutrients and foods are also especially important for vision health:

1. Dark Leafy Greens
2. Orange Pepper
3. Organic Pastured Egg Yolks
4. Wild-Caught Alaskan Salmon
5. Astaxanthin

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