Glow Behind Eyes

[eve1974]

So ... out with dogs tonight with a torch:... got me thinking....

When a person (or animal) dies wld their eyes still “glow” when a torch beam shone in them? Wld a dead person / animal still get that “red eye” effect when a photo is taken with a flash?

If not.... then what causes the “glow” in a living creatures eyes?

[woofgang]

its a reflection of the back of the eye https://www.goodeyes.com/blog/red-eyes-photos/

[woofgang]

and why they glow green https://text.npr.org/96414364

[eve1974]

Great!! Thanks woof! Very interesting!!

Reading the red eye explanation then it wld seem that if a person is no longer alive that red eye wldnt occur.

[Ken4155]

Most pro photographers avoid red-eye by 'bouncing' their light off whiteboards or umbrellas.

[Khandro]

There's a very funny short story by James Thurber called the 'Topaz Cufflinks Mystery' first published in the New Yorker which this reminds me of, does anyone know it? https://www.newyorker.com/magazine/1932/07/23/the-topaz-cufflinks-mystery

[Peter Pedant]

have any of the biologists said tapetum?

https://en.wikipedia.org/wiki/Tapetum_lucidum

dim light - the retinal cells get a second go
which make them even sensitiver ( as alice wd say)
When I was doing Phys with sir colin blakemore ( sir later that is - much later) 3 photons was sufficient to fire a retinal cell.

which is just a little too many for 'is there a photon there?' if the cell doesnt fire. - quantum effects in retinal phys.

( light intensity so low that 'did that photon fire the cell?' competes with 'light intensity so low that was there a photon there?

we had really good visual physiology lectures at cambridge

[Peter Pedant]

glow behind the eyes
aristotle was one who said that light travelled out of the eyes to illuminate the object

[Peter Pedant]

thanks for the question eve
the wiki article is like my old zoo-otobly lectures
you have a sign - red eye and this is how a variety of animals solve it - now what conclusions can we draw from the info ?

evo devo has sortta changed a lot since they found a retinal mamalian protein in an insect eye
completely unexpected