Color Blindness Facts

The basics

• It's rarely "blindness". Most color-blind people see color, just a narrower range. Seeing only in greys is extremely rare.
• It's common. About 1 in 12 men and 1 in 200 women are affected.
• It's mostly inherited and lifelong. Inherited color blindness is stable, it doesn't get worse. Color vision that changes over time can point to an acquired cause.
• Red-green is by far the most common type; blue-yellow and total color blindness are rare.

Common myths

• Myth: color-blind people can't drive. They can, traffic lights are read by position and brightness as well as color, and color blindness alone rarely disqualifies drivers.
• Myth: it only affects men. It's rarer in women but real, see can women be color blind?
• Myth: glasses cure it. Color-blind glasses can boost contrast for some people but don't restore missing cones.
• Myth: everyone sees the same "wrong" colors. The experience varies by type and severity.

Living with color blindness

Day to day, the friction is usually small but real: judging ripe fruit, reading color-coded charts and maps, matching clothes, or spotting a red pen mark on a page. Many people develop workarounds, memorising the order of traffic lights, using labels, or apps that name colors. In some careers (aviation, rail, maritime, parts of the military and electrical trades) color vision standards apply; see the lantern test.

The upside and the curious bits

• Some color-blind people are better at seeing through certain camouflage, because they rely less on color and more on texture and brightness.
• Color blindness was first described scientifically by chemist John Dalton in 1798, which is why it's sometimes called "Daltonism".
• Screening plates like the Ishihara test have been used for over a century.

Curious about your own color vision? Take the free test, it takes about a minute.