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LOG
04-17-2010, 05:45 AM
What would you call an eye that glows with its own light? Is there a word for a natural light-generating source?

Also, is there a word for an eye that possesses two sets of irises, or maybe it's an iris just holding two different colors...

Questions arose from this picture (http://starwars.wikia.com/wiki/File:Zillo_Beast_eye.jpg).

William Haskins
04-17-2010, 05:51 AM
http://en.wikipedia.org/wiki/Tapetum_lucidum

Lhun
04-17-2010, 06:24 AM
What would you call an eye that glows with its own light?Sauron?

Is there a word for a natural light-generating source?Bioluminescent/Bioluminescence. It's the thing fireflies do. Basically, they create two chemicals which emit light when they react.
Also, is there a word for an eye that possesses two sets of irises, or maybe it's an iris just holding two different colors...I don't think so, there'd have to be an animal with two irises to create the need for a name, and i don't think there is. Having two irises wouldn't serve any purpose either (just like a camera doesn't need two shutters) so i doubt it would evolve in the first place. A multicoloured iris is easily imaginable. Iris colour is pretty much a random occurrence anyway, it has to be strongly pigmented to block light, but what colour it is doesn't matter. One could even imagine a creature having a reflective iris.
I'd interpret the eye in the picture as simply showing an iris that's the same color as the "white" of the eye. (Or the other way around)

leahzero
04-17-2010, 06:36 AM
What would you call an eye that glows with its own light? Is there a word for a natural light-generating source?

Yes: "bioluminescence (http://en.wikipedia.org/wiki/Bioluminescence)."

Fenika
04-17-2010, 06:40 AM
Keep in mind that naturally glowing eyes are the reflection of the tapetum as already pointed out.

Pics- http://images.google.com/images?um=1&hl=en&client=firefox-a&hs=jWy&rls=org.mozilla%3Aen-US%3Aofficial&tbs=isch%3A1&sa=1&q=tapetum+lucidum&aq=f&aqi=&aql=&oq=&gs_rfai=&start=0&social=false

There's two dissected eyes there. The tapetum usually covers half the area behind the retina and is used to increase vision. Seen more in nocturnal animals.

efkelley
04-17-2010, 10:05 AM
The only potential I could see for multiple irises could be for telescopic/microscopic vision. But then you also need different lenses. Unless the secondary iris could distort the primary lens to allow for the enhanced vision.

Yeah, not seeing it from a purely science-minded viewpoint. Still, if you really want to have multi-colored irises serve a useful purpose, just use the whole 'we're not sure why, but it works' thing.

LOG
04-17-2010, 10:26 AM
http://en.wikipedia.org/wiki/Tapetum_lucidum

I thought of that, but it didn't quite work. That eye pic I linked, you could see light rays extending outward from its eye, even when it was in darkness.
I think bioluminescence would be the more likely culprit, especially since it was created to be both a subterranean and surterranean (is that the correct prefix for above?) hunter.

SaraP
05-08-2010, 03:50 AM
You can go one step further. There is something called Green Flourescent Protein (http://en.wikipedia.org/wiki/Green_fluorescent_protein). Because the gene sequence for its code is known, it is commonly used in molecular biology, made by bacteria. I can very well imagine a creature that has the gene for it, storing it in little tiny pockets in its eye so that it is released when the creature is in darkness. Kind of the same mechanism that allows the pupil to dilate or the way the skin in squid changes color.

You can also couple it with the double iris, where you have, for example an inner iris that works normally, and an outer layer, an outer iris, that has little pockets of GFP. As light fades, the inner iris expands, stimulating the outer iris to release the GFP. Not only you have a proposed mechanism of action, you also get the glow from the GFP to act as stimulant/light for the inner iris to work.

Kitty Pryde
05-08-2010, 04:01 AM
There is one species of squid that have biolumminescent eyes. They can basically swivel them around and look for prey and they are like a spotlight plus an eye in one! Which is rad! It's pretty exciting. I can try to look up the specific species. I think I read about it in "The Search For The Giant Squid".

ETA: DUDE! http://www.nationalgeographicdigitalmotion.com/clips/4470081_068 But I still don't know the species...

ETA again: FOUND! http://www.amazon.com/Search-Giant-Squid-Richard-Ellis/dp/1558216898#reader_1558216898 It's Histioteuthis dofleini, the flowervase jewel squid. The photophores of the smaller eye "may function as a searchlight". Hurray!