It’s all about the brain. You see, each eye sends its picture to the brain, and the brain puts them together. So you get one picture.
The brain can’t tell the difference between two pictures taken at the same time, so it just sees one picture. But if your eyes are separated by a little distance, then the two pictures will be slightly different from each other, and your brain will put them together differently.
So if you were a praying mantis, for example, and wanted to see an ant up close on one side of your head and a leaf on another side of your head (both at once), then having two eyes would be good for that. But if you want to see an ant close up AND an apple tree far away at once (or even an object far away AND another object far away), then having two eyes isn’t so good because they give two different pictures of what’s out there around you — which makes it hard for your brain to figure out what’s really happening around you!
So instead of having two “eyes” like humans do (which is what most insects have) — they have six or more “eyes” that are grouped together into one big compound “eye”.
Last modified: October 13, 2022