Princeton's WordNet(0.00 / 0 votes)Rate this definition: 1  shimmer, play(verb) a weak and tremulous light. 2  shimmer(verb) shine with a weak or fitful light. 3  shimmer(verb) give off a shimmering reflection, as of silk.
Cats, like humans, have both rods and cones in the retina. Rods are the receptors that the eye uses for night time viewing and sudden movement. Cones are used during the daytime, and process color information. Cats have more rods than cones, as compared with humans, making cat night vision superior to humans.
0.00001. 0.00001. People with normal color perception have three different types of cones. Each type of cone is tuned to perceive predominantly long wavelengths (reddish), middle wavelengths (greenish), or short wavelengths (bluish), referred to as L-, M-, and S-cones.