Pupils like a cats

Earthhorse

So I'm wondering if someone can help me out here. This is just a general question which I've had on my mind regarding the human pupil (and no, it's nothing to do with drugs or alcohol).

Anyway, I was standing at the back door to my friends house when his housemate told me to, "Stop doing that with my eyes". I asked what given that the only thing I was doing with my eyes was holding them open (along with the occasional blinking). He called my mate over and eventually they got a mirror and showed me what was happening. Whatever way the sun was shining in my eyes the pupils had become two narrow vertical slits quite like a cats sometimes are.

I'm just curious to know what conditions could create such an effect. I've never seen it before and a Google results in nothing directly addressing this. Even a half assed explanation as to how this could have happened would be interesting.

jill_valentine

I used to know a guy who had eye like that permanently. I had assumed that it was just a sort of harmless eye defect, but I didn't know it was even possible to ...er...switch back and forth...

Sleipnir

Do you have webbed feet and hands?
can you shoot spiderwebs from your wrists?
It could be a symptom of something altogether more.........sinister.........



(sorry, it's friday and I'm in a very 'meh' mood)

GuanYin

Human pupils, have a circular ciliary muscle that controls size variation and limits the size and shape of the pupil. Cats on the otherhand have two ciliary muscles that act in a shutter-like fashion. This gives the cat it’s a slit-like pupil in bright light conditions.

The shape of a cats eye is controlled by light and some neurochemicals, notably adreno-stimulants.

Its unlikely that you have two ciliary muscles unless you have some genetic condition, it wa smost likelya trick of the light. Maybe go to an optician, that your best bet really.

GuanYin

Originally posted by Sleipnir
(sorry, it's friday and I'm in a very 'meh' mood)

I think you'll find it's Thursday!

Earthhorse

Ah well, it's not like it's a medical problem or anything, I was just wondering what unique conditions could produce this effect given that I'd never seen or heard of anything like it before.

I don't what you mean by trick of the light syke. Do you mean that the pupil appeared to be slit like but actually wasn't? That seems unlikely to me for some reason.

And Sleipnir my spidey sense tells me it's not Friday (though it does feel like one!).

Sleipnir

Friday, Thursday, meh.

Stark

Holy crap, that's fascinating. Can you post pictures?

Earthhorse

If you're addressing me, then no. We didn't think to take pictures at the time. Or else we did and decided that my eyes might explode if exposed to a flash (exactly like a cat's, right?!)

Maybe I'll try and recreate the effect over the weekend. It'll give me something to do anyway.

Stark

Earthhorse

That's what I'm talking about.

Only mine was au natural (that's done with a lens).

Syke

that was very freaky

his_dudeness

Woah! That sounds pretty cool.

I've got a slightly-less-obvious but very much more permanant version of it, both of my pupils appear to "droop" and as a result, my pupils are not circular but rather are similar to Cats eyes.

My condition is genetic (called bilateral coloboma of the Iris) and results from a failure of the eye tissues to fuse properly during the early weeks of development.

I don't know what yours is but could well be just a whole trick-of-the-light thing, I doubt the Iris is able to move in that way

jill_valentine

That sounds interesting...I don't suppose you could post pictures..?

Nala

Originally posted by Earthhorse
decided that my eyes might explode if exposed to a flash (exactly like a cat's, right?!)

Eh...no.

Actually, while we're on the subject of cats and pupils, does anyone know why a cat's pupils contract in sunlight, but not in artificial light?

Bottle_of_Smoke

maybe something to do with uv light, most artificial light doesnt produce any uv (tho thats all im basing it on)