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. The retina has three types of cones. Each cone type is sensitive to one of three different colors â red, green, or blue â to help you see different ranges of color. Together, these cones can sense combinations of light waves that enable our eyes to see millions of colors. cones sense colour in the eye.