Humans trichromatic retinal cones
Humans have only three color (trichromatic) retinal cones. Red Green and Blue color receptor cells but within this color space humans can distinguish roughly 10 million colors.
blue cones (S)= short wavelength, red cones (L)= long wavelength, green cones (M)= medium wavelength.
However 50% of women are functional tetrachromatic and have enhanced ability at color discrimination based on retinal changes ie on the X genes (they have two) and can have different copies of either the long or medium wavelength cones making them functional tetrachromats.
Who said that women were the weaker sex. More on color this year.
© Emile Abbott
Copyright for this gallery photo belongs solely to Emile Abbott. Images may not be copied, downloaded, or used in any way without the express, written permission of the photographer.