Comparison of a deer fly eye viewed under a scanning electron microscope at different magnifications. The large, green iridescent eyes of the deer fly are made up of thousands of individual lenses which allow the fly to see in slow motion. Each lens is approximately 25 microns in diameter. Note the short, protective hairs that emerge from the eye's surface between some of the lenses. (Magnification from left to right: 260x, 440x, 4,000x, 8,000x, and 20,000x at print size 8"x11")