There are three main types of color vision deficiency: red-green, blue-yellow, and complete. Color blindness, or color vision deficiency, affects the way you perceive color and can make it hard to ...

The most common types of color blindness, or color vision deficiency, are genetic. However, other types may develop due to injuries, eye diseases, health problems, and side effects of treatment.

What color is a tree, or the sky, or a sunset? At first glance, the answers seem obvious. But it turns out there is plenty of variation in how people see the world—both between individuals and between ...