🎨 Why are men much more often colorblind than women?

The ability to see the full visible spectrum remains a mystery for nearly 300 million people worldwide. Men are significantly more affected than women by this condition, a disparity that puzzles researchers.

Cones, the cells located at the back of the eye, play a key role in color perception. There are three types, each sensitive to a specific wavelength: red, green and blue. Malfunction or absence of these cones leads to some form of color blindness.


Red-green color blindness is the most common form, resulting from missing or malfunctioning cones sensitive to these colors. Less common, blue-yellow color blindness affects blue cones. Cases of total color blindness are extremely rare.

The male predominance of color blindness is explained by genetics. The genes responsible for light-sensitive proteins in cones are located on the X chromosome. Men, with only one X chromosome, lack a backup copy in case of mutation.

Women, with two X chromosomes, often have a functional copy that compensates for any mutation. This significantly reduces their risk of color blindness, though they can still carry and pass on defective genes.

Promising research is exploring gene therapies to restore color vision. Using harmless viruses to introduce functional genes, these methods have already shown encouraging results in animals.