Sagot :
Answer:
Within the electromagnetic spectrum, people can perceive only a small portion of the wavelengths. (We can't see X-rays or Radio waves or UV waves.) Wavelengths are measured in nanometers (nm), and humans can see the wavelengths between ~400 nm and ~700 nm (the visible spectrum).
These light wavelengths are not colored, but our brains convert them to perceptions of color. Our brain uses the response of cone cells in our eyes to process color information. Cones only work in bright light. We also have rod cells in our eyes, and they are used in dim lighting. Therefore, color is something that our brain perceives, and not everyone or every animal sees the same color view of the world.
If our brains were not able to process these wavelengths into color perceptions, we would only be able to see in shades of gray.
*Interesting Fact: The rat is the only mammal that perceives the world only in shades of gray.