This digitally colorized scanning electron microscopic (SEM) image revealed some of the ultrastructural morphology displayed on the head region of a bedbug, Cimex lectularius. This is a close view of one of the insect’s compound eyes, which had been colored red. The compound eye is given this name, because the single large eye is really made up of many repeating units known as ommatidia. Each ommatidium is composed of separate units made up of a photoreceptor cell, support cell, and pigment cells. Though each of these visual mechanisms functions as a separate organ, together they provide the organism with a compound picture of its environment.