Have you ever wondered how the human eye sees different colors? People remember objects by knowing their color. Some people want to purchase stuff because it is their favorite color. The truth is that the objects we see do not possess any color since they only reflect the wavelengths of light. These wavelengths of light are perceived by the human brain as color. For humans, the visible spectrum ranges between ultraviolet light and red light. Humans can distinguish up to 10 million colors as scientists have estimated.
The object absorbs the light that hits it which reflects the rest of it. In the human eye, the reflected light enters through the outermost part of the eye or the cornea. The pupil is the part of the eye that controls the amount of light that hits the lens. The light is bent by the cornea toward the pupil. With this, the lens focuses the light on the layer of nerve cells in the back of the eye or the retina.
Do Cones Influence Color Perception of Humans?
Rods and cones are the two different types of cells in the retina that can detect and respond to light. Photoreceptors are the cells that are sensitive to light. If you are in a room with low or dim light, rods are activated. If you are in a room that has a brighter environment, cones are stimulated. Most people have about 110 million rods and 6 million cones.
Photopigments or color-detecting molecules can be found in cones. The three types of photopigments that humans have are red, green, and blue. In the daytime, the reflected light in a lemon activates both red and green cones. A signal is sent to the visual cortex of the brain which processes the number of cones. The color yellow can be seen after the nerve impulses are processed.
At night or in a darker environment, the reflected light in the lemon will stimulate the rods. Shades of gray can only be seen if only the rods are activated. Color constancy allows a person to see the same color of an object in different conditions.
What Are Color Vision Anomalies?
If one or more of the cone types are missing or not functioning, color blindness can occur. The most common type of colorblindness is red-green followed by blue-yellow color blindness. Men have a higher risk of having color blindness than women. Currently, scientists are developing new treatments for color blindness.