Different animals look at the world with different eyes, literally. The colors a species can perceive is dictated by the types and number of visual pigments found in the retina. Humans and most primates are trichromats, meaning we have three pigment varieties that absorb light in our eyes and then transmit that information to the brain. Some birds and reptiles have four pigments, allowing them to perceive ultraviolet wavelengths that we can’t. And other mammals have just two pigments.

This article from Scientific American examines how our color vision system may have evolved. And through their experiments, authors Gerald Jacobs and Jeremy Nathans discovered some intriguing brain adaptability when new sensory inputs are added.