It’s time for Trilobite Tuesday! Unlike any modern eyes–whether they are anthropoid, arthropod or annelid–the lenses of trilobite eyes were actually constructed of calcite. This provided these ancient creatures with virtually unparalleled vision that was filled with streams of light and bursts of color, based on recent experiments conducted with calcite crystals. With the complex geometric symmetry presented by each lens, such as those displayed on this Eldredgeops milleri, these eyes seem to defy their incredibly ancient ancestry. When we look into the fossilized eyes of a trilobite, it takes only minimal imagination to sense that these primeval creatures may indeed be staring back at us, providing a dramatic link to life some 500 million years in the past.