Final answer:
The individual units of compound eyes in crustaceans are called Ommatidia.
Step-by-step explanation:
The individual units of compound eyes in crustaceans are called Ommatidia. These ommatidia are the functional units of the compound eyes and contain all the necessary structures for capturing and processing light. Each ommatidium consists of a lens, a crystalline cone, and a cluster of light-sensitive cells called photoreceptor cells.