Science Questions

Why are insects, which have composite eyes, not blinded by the sun? Apparently they have no eyelids that they can shut, and my friend Wendolin blinded some ants with a laser pen and it appeared they were quite irritated by that. Lydia in Austria

I think they probably were quite irritated. Insects can be temporarily blinded by very bright light, but when they go into the dark again, their photo-pigment would be regenerated. There are some ants that live in very bright conditions in the desert. They would have pigment that would protect their sensitive photocells. In addition to that, all their neural machinery behind their eyes would act to adapt to avoid bright lights. The whole system is geared up to adjust the gain, like if you point a video camera at a bright scene. You can see that the camera adapts. That's what an insect would do if it lived in a very bright condition.

June 2006