How do insect eyes work?
If they don't have eye lids, how do they deal with dust and sand?
How far can they see -- a few feet?
Do any insects see in color?
Can large insects, with larger eyes, see farther or clearer than small insects? Or does a house fly have the same depth of focus and resolution as a fruit fly?
- Midnite RamblerLv 710 years agoFavorite Answer
Insect eyes are what is known as "Compound Eyes"
In Compound Eyes, there are hundreds of small "sub-eyes", each like a tiny telescope and each pointing in a slightly different direction. If you look at photographs of an insect eye taken at high magnification you'll see that the surface seems to be a mosaic of little hexagons - each is the outer surface of one "sub-eye".
As each "sub-eye" points in a slightly different direction, the insect sees lots of slightly different views of its surroundings from which it can work out the direction of an object and it's distance (in the same way we do using our binocular vision)
Compound eyes cannot focus and are generally set at relatively close ranges as this is where their food is and where threats from predators are most likely. They are particularly sensitive to movement as a moving object passes from the vision of one "sub-eye" to another.
Insects have very good colour vision - which is why flowers are brightly-coloured (to attract insects such as bees). Insects generally see light the same as we do but are also able to see Ultra Violet light which is outside our range of vision (some flowers reflect in UV specifically to attract insects - they look plain to us but have patterns in UV)
Larger compound eyes probably can't see any further but their vision is clearer - think of it like dividing a picture into pixels... the more pixels the clearer the picture. Each pixel is provided by a "sub-eye" so the more there are then the more pixels. This is illustrated well by looking at dragonflies who are visual predators and have huge eyes relative to their overall size. Compare them with termites which have tiny eyes as they spend most of the time in the dark and operate mainly by touch and scent.