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).
Vision and color perception. 1  Human eyes have a light-sensitive layer--the retina--which carries two types of light-sensitive cells: rods and cones. Rods are sensitive to dim light (scotopic vision) but do not provide color information. 2  For greatest acuity look straight; for greatest sensitivity, look to the side.