Insects have simple eyes known as what?

Insects have simple eyes called ocelli. These are small, simple eyes that typically consist of a single lens and are designed to detect changes in light intensity rather than form images. Ocelli are often located on the top of an insect's head and play a crucial role in helping the insect orient itself in its environment, navigate, and detect movement. They complement the larger compound eyes, which are composed of thousands of tiny lenses (ommatidia) allowing the insect to see a wide field of view and detect rapid movements. This combination of simple ocelli and complex compound eyes enhances an insect's ability to respond quickly to changes in their surroundings.

Other options such as compound eyes refer to the multifaceted structure that gives a wide-angle vision, ommatidia refers specifically to the individual units of the compound eye, and filiform eyes are not a standard term used in entomology. Thus, the choice of ocelli accurately identifies the simple eye structure found in insects.