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.
Cones are most helpful in normal or bright light. There are 3 types of cones - red, green, and blue - to help you see different ranges of color. Together, these Cones sense combinations of light waves that enable our eyes to see millions of colors.