Question

What is the difference between simple and compound eyes?

Answer 1

Simple eyes	Compound eyes
1. Simple eyes contain single lens and several sensory cells.	Compound eyes contain several lenses (around 2000) called ommatidia (sing. Ommatidium).
2. Single lens collect light and focuses onto retina to form a single image	Each ommatidium forms an image of an object thereby forming several images of an object.
3. Simple eye does not form a complex image but can detect movement of the object.	Compound eye forms a complex image of an object 1 and detects even a slightest movement of the object.