why is the pupil of the eye black?
80031
Pupil of the eye is not black.It is just a space for the light can pass and can form an image on Retina.Since there is dark inside our eyeball,it appears to be black.
883493
It's genetic in most people.\n\nThe second main cause is a change in melanin levels in one eye, this can be because of illness or trauma to the head.\n\nFor others a trauma to the head can jolt the blood vessels in the eye causing a change in colour
17484
black is the absence of color
304013
~4% of light is reflected back at normal incidence (standing in front of the mirror).  In order to see the reflected image of yourself, the light that is reflected should be brighter than any light coming through the glass.  If the glass is black, it means that little light passes through it, so it should be fairly easy to see your image.  This is also why it it is easier to see your image in transparent glass if it is brighter in the room on your side of the glass than on the other side.
884199
except that the pupil is not an organ
29885
You ask an interesting question.  The iris/pupil area that you are referring to is actually your cornea (the iris and pupil are located a few millimeters behind your cornea).  There are nerves in the cornea and in the rest of the front of the eye.  Being poked anywhere in the eye typically hurts.  One reason you may not feel as much when you touch your cornea is that you are a contact lens wearer.  After wearing lenses for some time, your cornea gets used to touch and your threshold for pain increases.  You want to be sure that your contact lenses are transmitting enough oxygen so that the nerves in the cornea aren't becoming anesthetized.  See your optometrist or ophthalmologist yearly to evaluate your contact lenses and the overall health of your eyes.
72663
Its a cute question. :-)\nLet me explain it this way.\n\nShadows arent necessarily objects themselves. \nThey are just a patch of surface, which dont recieve direct light from the source (sun, lamp etc), but only recieve the scattered rays of light. \nAnd for this reason, these patches are dimly lit, making it look darker than the surrounding, which in our daily terms is 'black'. :-)
799871
It looks black.  When something absorbs all wavelengths of light t appears black.
598553
It is blood vessels near the surface of the skin where blood pools on some individuals giving them the tired look. In extreme cases black eyes. Using a cool cloth will help some what. Caffeine and smoking aggravate it. It is found most often in brunettes.\nIt can also have medical reasons so see your doctor for advice hope thst helps
594651
Its a high frequency low wavelength light.can you see UV? no right? so it appears black.. also its monochomatic that you dont see the tinge of other light or colour...
30723
In order for your eyes to register something, light must first be shined on, and reflected off of a particle.  If the light has nothing to reflect off of, your eyes will not see it.  Space consists of nothing, making it appear completely black to your eyes.
219049
The pupil is the black part of your eye. The iris is the colored part. If you really are seeing a lighter color in the pupil, it could mean you are developing cataracts or that something is wrong with your lens (which sits in front of the pupil). Go to your eye doctor and have it examined. If you are talking about the rim of your iris, that often lightens as you get older. The outer edge looks very sharp in a child's eye, but if you look at older people, the edge of the iris looks as if it is more blurred because of a whiter rim. This is normal.
144504
no, it does not. in physics, balck is not a colour. in the visible part of the electromagnetic spectrum, there is no black. a total absence of any colour is represented by black in physics. black holes are so named because they have such a strong gravitational force that they even attract light and do not allow it to escape. hence the name
518860
I don't think that can be a cause, lazy eye is from a tiny muscle in your eye.  You might be more aware of your eye when your pressure is up, because your pupil is more dilated.
570792
There are also, rarely, some people whose eyes appear aqua or violet, as well as the pink-eyed albinos. Eye color is determined by the concentration and distribution of melanin in the iris, which affects how light is reflected by the iris. The limitations on eye color are probably the same as the limitations on skin color, which is all controlled by melanin.\n\nHere's a link to an interesting article on eye color.
502941
Eye color is believed to help protect your retina from the sunlight, but that's not really true -- it doesn't matter.\n\nYour iris is made up of fibers, and the colors vary, depending on your genetics. There's no real explanation to why eye color is the way it is.
853151
it's pressure and blood flow...  this sensation of course you know soon fades...\n\nthe optical nerve fills with blood while you are pressing on it and that's what it looks like.. normally the blood circulation looks like swirling clouds in your eyes when the lids are shut.\n\n:D