Do fly has monocular vision or stereoscopic vision?

Flies primarily have monocular vision, as their large compound eyes consist of thousands of individual ommatidia that provide a wide field of view. This allows them to detect motion and changes in their environment effectively. However, they do have some degree of stereoscopic vision due to the positioning of their eyes, which can help them gauge distance, although it's not as pronounced as in animals with more complex eyes. Overall, their vision is adapted for detecting movement rather than depth perception.