One of the first things children learn in school are the colors of the rainbow: red, orange, yellow, green, blue, and violet. For people with normal color vision, it’s relatively easy to distinguish between those six colors. For someone with deficient color vision, or “color blindness,” it isn’t so simple.
What is color blindness?
Two types of photoreceptors in the retina of the eye are responsible for how we see color: rods and cones. Rods and cones contain pigments that change when they detect light. Rods are triggered in dim or low lighting, and cones are activated in brighter environments. Cones have several types of photopigments that react to different wavelengths of visible light. Color blindness occurs when one or more of these pigments is missing, or isn’t functioning correctly. Contrary to what many people may believe, in most cases, color blindness doesn’t mean a person can’t see color. Complete color blindness (seeing in black and white), which often impacts clearness of vision as well, is extremely rare. The majority of people with color blindness can see color, but they see a smaller range of color. For example, according to colourblindawareness.org, if a person with a moderate form of red-green color blindness were looking at a box of 24 colored pencils, they’d likely only be able to accurately identify the color of about five pencils. Red-green color blindness is the most common type, and is caused by loss or limited function of the red (protan) or green (deutran) cones. Blue-yellow color blindness, or Tritan color blindness, is less common than red-green, and is caused by missing or limited functioning blue cone photopigments.
Who gets color blindness?
According to the National Eye Institute, the common form of red-green color blindness is most prevalent among people with Northern European ancestry, affecting about eight percent of men and 0.5 percent of women. The inherited colorblind gene (the most common type of color blindness) appears on the X chromosome, which is why men are more likely to be affected than women. Males only have one X chromosome, while women have two—which means both of their chromosomes would have to carry the gene for them to inherit the deficiency. Trauma to the eye, as well as certain eye-related inherited diseases, can also lead to color blindness, though they are all quite rare.
How do I know if I’m colorblind?
The symptoms of color blindness are not usually detected by the person with the color deficiency, but rather the people around them. That’s because color perception is individualized, and if you’ve always seen color one way, there’s no way you can know that your perception of color is abnormal. Parents are most likely to notice symptoms when a child is learning colors. Symptoms include difficulty seeing colors, or the brightness of colors, and the inability to distinguish between shades of the same or similar color. Eye care professionals diagnose color blindness using a variety of color tests.
Are there treatments for color blindness?
Although there is no cure for color blindness, there are various tools and visual aids that help people cope. For people with red-green colorblindness, there are special glasses that can help them see colors more accurately. There are also apps, like Color Blind Pal, that help people with color blindness discover the color or shade of an item, which can be particularly helpful for things like selecting ripe fruit or shopping for clothing. Many phones and computers also have colorblind modes, which will adjust the color on your device to create better contrast.
