This scanning electron micrograph (SEM) revealed some of the ultrastructural morphology displayed on the head region of a bedbug, Cimex lectularius. Of interest is one of the insects compound eyes.The compound eye is given this name due to the fact that 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