Apart from tranducing into signals to pass through the optic nerve into the brain, what becomes of the photon particles themselves after they've been transduced? Can they leak into many types of cells beyond the gates of the visual receptive field?

Or, if I were to posit a poorly constructed thought experiment well beyond my level of study, are they perhaps carted along astrocyte colonies and carried as nutrients to neurons to serve as the material from which the imaginative visual field is constructed?

I believe the photons(light) reflects back. Not 100% sure though.

Keep in mind that photons are electromagnetic waves resonating at certain frequencies.

Photons are merely radiation energy. When the photon strikes the photoreceptors, it alters the shape of a molecule (rhodopsin??). This is an endothermic chemical reaction which can only occur if energy (photon) is "consumed." Of course, the molecule is unstable in this state, so it eventually returns to it's previous state. I believe the energy is then used to perform work in the cell.

As for the rest of the photons, most of them are absorbed by the eye. (The inside is black, and as we know, black absorbs light)

I doubt that light could "leak into the brain." I believe the optic nerve is pretty tightly bound (correct me if I'm wrong).

Aren't puples black because they absorb the light, and that is why when you take pictures with flash your eyes are red, because all of the light cannot be absorbed so it is reflected back? Seems like that is where the photons go to me~

It might be light reflected off the lens. You can get the same effect if you take a picture of certain semi-transparent surfaces (i.e. if you take a picture though a window, the flash may appear similar).

The pupil is actually transparent. It's the choroid inside the eye that gives it the black color.

EDIT: I checked wikipedia for info on the red eye effect and I found this:
The light of the flash occurs too fast for the iris of the eye to close the pupil. Light is focused onto the blood-rich retina at the back of the eye and the image of the illuminated retina is transmitted to the camera resulting in the red appearance of the eye on the photo

I'm not quite sure I'd fully endorse that answer though. The red eye effect seems too pronounced to be light reflected from inside the eye. Plus, many animals frequently display gold/green/blue reflections. I dunno...

Besides, I've seen the inside of quite a few eyes; they were as black as tar.

Isn't the lense the only part of the eye that is truely transparent? Speaking of lenses, is it true that the cells in the lense have no metabolism? I heard somewhere that when the cells are forming they undergo a sort of cellular suicide, destroying parts of the cells (certain organelle I am guessing) such that light does not become displaced--is that true?

I have no idea, but I suppose it's possible. I know plants have certain cells which "commit suicide." This allow them to become hollow to serve another purpose. I think they can derive nutrients from the surrounding cells though.

It is indeed rhodopsin that is changed as the photons hit the eye. And yes, 'red eye' from taking pictures is caused from the light reflecting off the retina and through the pupil. I just got trained on an Eye Tracker and they talked about that.

The actual color of red comes from light being reflected back from the retina that gives it the red-ish color from the blood vessels.

Why do animal eyes (dogs, foxes, cats) reflect back as blue or green? I realize that their choroid is often lighter in color (to improve night vision), but wouldn't their blood vessels still color it red?

I honestly don't know, and I'm very curious now.

My bad, I dono what I was on when I wrote that photons are reflected. I had just been in a lengthy several day discussion on electromagnetism, quantum mechanics and modern quantum chemistry. I think I mixed some information from an entirely diffrent topic with this one.

My bad, I dono what I was on when I wrote that photons are reflected. I had just been in a lengthy several day discussion on electromagnetism, quantum mechanics and modern quantum chemistry. I think I mixed some information from an entirely diffrent topic with this one.

Casey, for starters, animals have an extra coating -- the tapetum lucidum (sp?) -- it's a reflective tissue found behind the animal eye’s retina. Therefore, this tissue allows for animals to absorb light that is barely even present. I have no clue how it works... but that sure would be fascinating to know and trace its time through evolution.

On that note, all bodies above absolute zero produce some form of radiation, this includes photons.