Flies have small brains that would not be able to process high-resolution images such as those that we see with our own eyes. Instead, they’ve perfected the use of compound eyes, composed of a dense mosaic of tiny eye-like structures called ommatidia. Each ommatidium consists of a microlense that focuses light from a specific section of the insect’s field of view onto an independent set of photoreceptors. Think of it as having many low-resolution cameras pointing in different directions. The result is a vision system with low spatial resolution (i.e. it can’t see details), but a wide field of view (i.e. it can see all around). By comparing information across the different ommatidia, flies can extract temporal information useful for detecting motion. This motion information, also called optic flow, is what allows flies to navigate, take-off, land and avoid obstacles while using very little processing power.