Bioluminescent Eyeballs?

Some creatures eyes can reflect light to see in low light conditions but would it be possible for a creature to have bioluminescence producing light from inside it's eyes and allow it to see in total darkness?

P.S. I know there are several types of fish with glowing patches beneath their eyes but i'm talking more of a glowing membrane or organ within the eye.

Edited by Kaiseror on Dec 2nd 2018 at 3:52:30 AM

That's actually the opposite of helpful. If you produce light from inside your eyes, you'll blind yourself, never mind stand out very visibly to anyone looking for you. This is the same basic idea as the trope In Space, Everyone Can See Your Face.

Sea creatures don't have bioluminescence so they can see other things. They use it to attract things to them, such as mates or prey.

Edited by Fighteer on Dec 4th 2018 at 10:13:31 AM

So it would be detrimental to a creature with eyes like ours that collect light. Would an eye designed only to utilize it's own bioluminescence be feasible, like somekind of alien that lives in a subterranean ecosystem?

In general, no. Glowing eyes would wash out the rest of the world making the eyes basically useless.

The eyes would see their own light far more brightly than anything it could illuminate. Added to that, generating light takes energy, and you'd need a powerful light to see anything more than a meter or so away from you. There's no way something like that could evolve since it would provide no advantage to the organism and be extremely disadvantageous in terms of attracting predators.

That said, the kind of light matters. I can imagine some sort of weird creature that emits light at specific wavelengths, like a fluorescence illumination system. Their eyes, in turn, are sensitive to different wavelengths that would only occur in the reflected (emission) light, possibly wavelengths that would be produced when their excitation light interacts with specific types of creatures. ^note More specifically, interacts with autofluorescent molecules in their bodies. In this way, their bioluminescence acts as a kind of radar searching for exactly those species that they prey on.

This would be a really complex system to have evolved naturally, but it is at least feasible from a physics perspective. There's also no inherent reason why the excitation light would have to come from the eyes as opposed to other organs evolved for that purpose, although if the eyeballs are internally reflective, it would allow the light to be beamed in specific directions instead of going everywhere.

The best part is that, if you do want to portray an organism that beams fluorescence excitation from its eyes, you can justify calling it the "laser fish".

Edited to add: UV light is strongly absorbed by water, so UV fluorescence illumination, like a natural blacklight, would work quite poorly underwater.

Edited by Fighteer on Dec 6th 2018 at 10:46:30 AM