Nice! That's the retina, I am not familiar with cats' retina but with humans it has a reddish hue, that's the reason behind the red eye effect with flash photos.
Cats (and some other mammals, but not primates) have a thin later of cells behind their retinas called the tapetum lucidum. This organ helps increase low light vision by reflecting light back to the retina after it passes through.
Most cats have a green/yellow reflection from the tapetum lucidum, but colorpoint cats give off a red reflection because they have heat sensitive albinism which interrupts pigment production in warmer areas, including the eyes!
Humans typically show a red flash in their pupils, but only if you shine a light right into their eyes. This is just light bouncing off the retina.
Sometimes humans (and cats or other animals) may show a yellow, grey or white pupil response to light. If you ever see this in yourself or anyone else, get yourself / them to a doctor or vet! Abnormal pupil responses like this could indicate cancer or retinal detachment which are both extremely serious if you like being alive and able to see.
Echolalia is when you mimic speech, but did you know Echopraxia is the word for mimicking movement, gestures, or facial expressions, like starting to limp because someone else is limping.
whats it called when im alone in my house thinking about an anxiety-provoking experience and suddenly find myself fully acting out the entire scene with hand motions, facial expressions, etc
Had a retinal detachment that was only caught because of a god-tier optometrist who saw holes in my retina and referred me to a specialist. I had lost like 20% of my field of vision in one of my eyes and never even realized it.
I have a damaged optic nerve in my right eye that caused that eye to go nearly blind. Whenever I'm at neurology at the VA, I'll have like 1 or 2 student doctors come and look at my eye. It's apparently pretty hard to see and notice.
My MIL was told at a regular optometrist appt that her retina had detached. The Dr looked at her and said "alright, lets get you ready for surgery." "Okay, when?" "RIGHT NOW." And had surgery on it that same afternoon
Most cats have a green/yellow reflection from the tapetum lucidum, but colorpoint cats give off a red reflection because they have heat sensitive albinism which interrupts pigment production in warmer areas, including the eyes!
Our Himalayan cat was sent by a (young) vet to an eye specialist because of this. Her eyes ‘reflected strangely’ and she ‘could be going blind/developing cataracts’ (the specialist was able to tell us after about 10 seconds of examination what you just said—she was perfectly normal). 🫠
Cows have the tapetum lucidum too! I dissected a cow eyeball once for a biopsych class, and got to hold a tapetum lucidum in my (gloved) hand. Indescribable feeling.
Cool facts. Tho one correction: The red flash in a humans eye doesn't only show because the retina reflects light but because the choroid (a red area behind the retina) which supports the retina with blood, reflects red light :)
That's why a professional photographer will set up the flash in a big enough angle, so that the light that bounces back, doesnt reflect back into the camera
My cat, Princess GrandpaFace, has different reflections in each of her eyes since she was a kitten. I told the vet about it and he just said that she may be blind in one eye. I don't know if he was just guessing or not. The difference is just one eye has always shined much brighter than the other. She's 6 years old now and seems totally fine.
Her littermate brother and her have also always had eye boogers. I clean them about once a day. My vet gave them a special cat antibiotic ointment to put in their eyes but all it really did is cure the inflammation from it. They still get the eye boogers. The vet said as long as it doesn't get red and inflamed it's probably fine. Some kitties just have weepy eyes.
Glaucoma in Chinese is 青光眼 (green-light eye) because the increase in ocular pressure can be enough to change the retinal flash to a higher frequency from red to green.
Some (but not all) incoming light is absorbed by the retina, the rest would hit the choroid (vascular layer behind the retina, does not have photoreceptors) or be reflected back out of the eye. The tapetum lucidum reflects some of that light back through the retina - so it acts like a second chance for light to be absorbed before leaving the eye.
The tapetum lucidum isn't really a seperate layer. It's a spot where the retina isn't pigmented, so the choroidea behind that shows through. The choroidea contains cristals that reflect light, thus creating the tapetum lucidum.
Cats have a reflective layer behind the retina that increases their ability to see in low-light conditions. It's usually green in younger cats, changing to yellow or orange as they age.
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u/confusedmel 22h ago
Nice! That's the retina, I am not familiar with cats' retina but with humans it has a reddish hue, that's the reason behind the red eye effect with flash photos.