h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Hey Anthea,

I've just asked this to Kham too, but you do Science and this is more of a bio q, so I figured I'd ask you.

I can't find this ANYWHERE in my text book or notes or handouts or the net or anything.

Anyways, is the pupil of the eye actually transparent and it appears black because the inside of the eye is black when looking from the outside in cause there's no light in there?

Cat

yes i beleve that is the case
i will check it with a bio teacher if you want....

The eye is formed by lots layers. I study the eye in my own language techinal names but i will try to be simple and understandble.

The eye is black in the inside because there are pigmented cells in the inner wall that absorbs light. This cells are the cones and cilindrical cells. The light enters throw the christaline, passes the vitrius liquid and reaches the inside of the eye globe. Inside ,the light stimulates the neural visual cells, wich have differents pigmets stimulated according to the intensity and frequency of the incident light. That is why in the inside of the eye globe appears to be black: because light is absorved in order to stimulate neural visual cells in order to appear an image of what you see in the brain. For even more precise information i advise to review the chapters about the eye of medical Human Physiology by Guyton Hall, or any other kind physiology book.

OK, didn't need that much information...

Well, I wrote that anyways, so all is good.

Cat