Cone monochromacy: It happens when 2 of your 3 cone cell photopigments -- red, green, or blue -- don’t work. When only one type of cone works, it’s hard to tell one color from another.

People see colors using specialized cells in the backs of their eyeballs called cones. There are three types of cone cells, and each is tuned to be most sensitive to certain wavelengths of light.

“There's actually three of them, there's a red, green, and blue cone.” The term color blindness is a misnomer, said Shelby. People who have the condition usually do see colors.

While humans have three color cones in the retina sensitive to red, green and blue light, birds have a fourth color cone that can detect ultraviolet light. A Princeton-led research team trained wild ...

Humans rely on sight, which is primarily mediated by three color-sensing cone types, to perceive the world in a kaleidoscope of hues. Blue cones develop earliest, followed by the morphologically ...

If you have real extreme color deficiency or are missing one of those cones, then our glasses can't help them.” That was the case for 11 News assignment editor Gary Sheridan.

When a cone is exposed to an excessive amount of the color it perceives, it becomes fatigued and unresponsive. This causes the only two cones that are still in use to respond by showing their ...