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.
CONE CELLS are the second type of light sensitive cells in the retina of the eye. The human retina contains 6-7 million cones; they function best in bright light and are essential for acute vision (receiving a sharp accurate image).
Cones reside mostly in the central portion of the retina, and allow us to perceive fine visual detail and color. 1  Image courtesy of Robert N. Fariss, Ph.D., chief of the NEI Biological Imaging Core, and Ann H. Milam, Ph.D., former professor in the Department of Ophthalmology at the University of Washington.