Genetics plays a big role in color blindness. Find out why men are more at risk, and other factors that cause the condition.

The human eye sees colors based on the wavelengths of the light radiating toward them. There are many colors in the visible spectrum, but not everyone sees those colors the same.

People with color blindness can’t see some colors, or colors may not appear as vivid. Color blindness can develop with age or with certain conditions, but in most cases it’s passed through families.

This article will explore how color blindness traits are passed from parents to their children, and why people assigned male at birth are more likely to have color blindness.

Language matters

Regardless of the gender you identify with in your daily life, we are all born with an embedded genetic code. Part of this code dictates our sex assigned at birth.

In this article, we use the terminology of “people who are assigned male at birth” to refer to individuals who were born with an X and Y chromosome. People who are assigned female at birth are born with two X chromosomes, so genetic traits are inherited differently. We also use the terms men and women to reflect the language used in studies.

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There are several causes of color blindness, but genetics is the most common. People who have some degree of color blindness usually have difficulty seeing reds and greens, and the red-green color deficiency gene is transferred through an X chromosome.

Since people who are assigned male at birth have one X and one Y chromosome, a red-green color deficiency gene passed on an X chromosome is likely to result in some level of color blindness.

People who are assigned female at birth are born with two X chromosomes, so the red-green color deficiency gene would have to be passed through both X chromosomes (by both parents) for color blindness to develop.

Since red-green color blindness is the most common, the rules of genetics mean that mothers who are assigned female at birth are most likely to pass this gene on to their children who are assigned male at birth.

Other forms of color blindness can also be inherited, but other color deficiencies — like blue-yellow color blindness— involve other chromosomes that aren’t affected by sex at birth.

A family history of color blindness is a big risk factor, but it isn’t the only one.

Some other risk factors that could increase your risk of developing color blindness at some point in your lifetime include:

Not all color blindness is genetic.

Red-green color blindness is commonly passed through families from mother to son on an affected X chromosome. Since red-green color blindness is most common, this makes it seem like all color blindness is inherited.

Other forms of color blindness can be passed through other genes that aren’t specific to sex assigned at brith, or they can be acquired through various illnesses or injuries over the course of a lifetime.

If you were born with color blindness, you probably never had to think about how to adapt.

Congenital color blindness is determined before birth, so the cones and rods in your eyes are physically incapable of recognizing certain colors. There are times when not being able to see certain colors can be inconvenient at best — or dangerous at worst.

Traffic lights, for example are usually red, green, and yellow. People who are colorblind usually learn the position of the lights that indicate “go” or “stop” in their region.

Special glasses or contact lenses can also help supplement color vision. Some jobs or activities may require you to take a test to check for deficiencies in your color perception so that precautions or steps can be taken to avoid any mistakes or dangerous situations.

Learn more about what color blindness is like here.

Color blindness can be inherited or acquired. When it’s inherited, or present at birth, it’s usually passed through the X chromosome, making this deficiency more common in people who are assigned male at birth.