how do roaches see?

Answer 1

Like most insects, they have "compound eyes". The image they see is quite different than the image we see. They see an image that looks like what we would see if we viewed an out of focus scene through an empty honey comb held a few inches from the face. They respond to light and movement, but do not see in sharp detail.

A Yahoo search for "insect sight" (include the quotation marks in the Yahoo search box) yields 136 results. If you do the same search, and are willing to spend a little time exploring, I'm sure that you will quickly find a lot of detailed information.

Good luck with your search for information.

Answer 2

Roaches and other insects have their own ways of seeing that are quite different than humans. They have compound eyes that are make up of hundredsof small units called omnatidia, each one collects light at an angle. The information is then sent to the brain where it is collected together to form an image. It is also indicated that roaches can detect changes in light dermally (through their skin) but it is unknown how they do this. Roaches also have small sensillae or hairs that cover many parts of the body and detect slight air movements. This, in combination with turning on the lights when you enter a room, causes roaches to scatter.