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Celia Cyanide
03-01-2006, 08:26 PM
Do insect eyes function differently that animal eyes? Where can I get a good, concise explanation of this?

I am writing a scene with two characters, and they are having a conversation about eyes. One of them mentions insect eyes, and that he thinks their eyes function a little differently then ours do. The second character is the type of person who finds everything interesting, and likes to share information he has learned. I need him to give a quick little explanation of how insect eyes work, and then back to their conversation.

Thanks in advance!

Maryn
03-02-2006, 08:35 PM
I asked our son (formerly called Science Boy, now rechristened) and he said that while he didn't know how they work, he remembered Mr. Stein saying that insects do not have the single image formed by two eyes and one brain that mammals (and reptiles?) have.

Apparently insect vision is like looking through one of those party-favor toys, the little plastic cone fitted with a 'cut' (molded plastic) lens that looks something like the inside of a car headlight, which produces a dozen or so images of whatever you're viewing through it, all at slightly differing angles. (We called them kaleidescopes, but they're more like prisms.) Here (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5637403225&category=3200)'s an image of the toy, in case I didn't explain it well enough. Anyway, because they've got images coming into receptors at every part of a bulbous eye, it gives them terrific peripheral vision--and lets they fly or jump out of the way of a rolled-up magazine.

Maryn, whose brain is filled with equally useless stuff

arrowqueen
03-03-2006, 01:20 AM
http://www.pbrc.hawaii.edu/microangela/solar.htm

Hope this helps.

Peggy
03-03-2006, 01:46 AM
I asked our son (formerly called Science Boy, now rechristened) and he said that while he didn't know how they work, he remembered Mr. Stein saying that insects do not have the single image formed by two eyes and one brain that mammals (and reptiles?) have. I believe true stereoscopic vision - where information from both eyes is integrated by the brain into a single 3D image - is limited to animals with both eyes on the front of their face, like humans and cats.
(I hope that Science Boy nickname didn't scar your son for life :))
Apparently insect vision is like looking through one of those party-favor toys, the little plastic cone fitted with a 'cut' (molded plastic) lens that looks something like the inside of a car headlight, which produces a dozen or so images of whatever you're viewing through it, all at slightly differing angles. According to this site (http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CompoundEye.html) "There may be thousands of ommatidia ["bumps" of the eye] in a compound eye with their facets spread over most of the surface of a hemisphere. [...] The composite of all their responses is a mosaic image a pattern of light and dark dots rather like the halftone illustrations in a newspaper or magazine. And just as in those media, the finer the pattern of dots, the better the quality of the image."

(Cool pictures arrowqueen.)

Charlie Watts
03-03-2006, 03:04 AM
Insects have compound eyes. They probably see many images at once. This helps them to see motion. They probably can't see detailed images like we do.

MadScientistMatt
03-03-2006, 08:55 PM
The description of a compound eye sounds like while it has a lot of lenses, there isn't a well developed visual cortex. Many times, there are less than ten light-sensitive cells behind each facet. Such an eye would probably generate an image like the pixelated images you see on the TVs when they are trying to blur a face (or other body parts), but they run at a much higher rate of frames per second.

This article here covers an exceptional insect where the individual eyes have some level of imaging capacity:

http://www.news.cornell.edu/Chronicle/99/11.18.99/insect_eye.html