Where Are the Eyes on a Cockroach?
WouterA cockroach’s eyes are compound, meaning that they have more than one lens. They’re located in the forehead, on the dorsolateral side of the head capsule. The compound eye is made up of around 2000 hexagonal compartments and functions to produce an image.
In addition to its two eyes, the cockroach has other structures that aid its vision. Its cornea contains several layers of cells that make up its lens. These layers create an ommatidium, or the visual unit, and these are organized in different patterns. This structure results in a cockroach’s mosaic vision. It also has a special structure called a rhabdome, which contains spindle-like cells that secrete a lens.
While cockroaches use their sense of smell and touch to navigate their environment, they can also see in the dark. Their compound eyes are made up of thousands of photoreceptor cells. In addition, cockroaches also have movable antennae that are fashioned like a mosaic. These antennae have thicker segments near the head and thinner segments near the tip. The cockroach also has mouthparts that are used to feed on food.
The ommatidia of an insect’s eye are highly pigmented. They’re made up of two types of ommatidia. The first type is called apposition eyes, while the second is called a superposition eye. The eyes of diurnal insects have a pigment sheath surrounding the rhabdome, while those of nocturnal insects have pigment that touches the retina.
