Why is the pupil of the eye black?
80133
I'm so not good at science, but isn't the pupil a hole? And the iris is a muscle surrounding it that contracts and expands upon exposure to light. If indeed it is a hole......perhaps this is why it is dark. *shrugs*
369741
The sky is blue to us beause of Rayleigh scattering.  From outer space, you don't have that atmosphere effect, so it's black.
778664
the sun heats up the molecules in the object expanding them slightly usually not noticeable to the human eye, black absorbs the light instead of reflecting it.
460962
Assuming they are completely blind, it's like having no eyes at all, in which case they would "see" nothingness.  Blackness would indicate an ability for your eyes to pick up at least some form of light, and completely blind people can't pick up any forms of light at all.
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
232489
its a clear protective coating over the pupil and the iris. the pupil is actually an empty space. the iris is a pigmented ring of muscle which when it contracts lets less light into the eye also known as pupillary constriction. when the iris relaxes the pupil opens up causing pupillary dialation. the more constricted the pupil the sharper your vision. but at night you need to let the maximum amount of light into the eye so the pupil dialates. the large opening causes less sharp visual acuity. the lens of the eye focuses light on to the retina behind it which is filled with rods and cones which are receptors. all the nerve cells and blood vessels converge into the optic disc and then into the optic nerve behind the eye. the optic nerves of both eyes intersect and combine signals which are sent to the occipital lobe of the brain in the back of your head. so actually you see with your brain
143118
Yes.  Black is the condition of no visible light reaching the eyes.  However, because 'colour' is an arbitrary way that humans identify the sensation of electromagnetic waves, the fact that 'black' can be sensed makes it a colour.  However, black can either be the absence of all light or the combination of many other colours.
759932
you have to paste it around the eyes to get comfort from black eyes
408653
Most babies have blue eyes when they are born and then their eyes darken as they age.\n\nWhen someone has two eyes of a different color it is pretty rare and usually results from some sort of genetic loss of pigmentation or can result from eye trauma.\n\nThe basis of eye color mostly has to do with melanin pigmentation.  If you have a lot of melanin you have brown eyes if you have very little you have blue eyes.  Everyone else is somewhere in between except people with green eyes which can result from flecks of yellowish fatty pigments against a dark background.
1087794
Technically, black is the absence of color. We only see certain colors because those colors are reflected (i.e. they aren't absorbed). We see black because the substance absorbs all color wavelengths, and hence no colors are reflected back.\n\nCombining a large number of colors will yield a black "color". Try Red, Orange, Yellow, Green, Blue, Indigo, Violet.
904553
Not many people have black hair and blue eyes, but the effect is pronounced and quite lovely.\nHaving natural Black hair and blue eyes is commonly a Celtic trait.  If you are of European origin, my guess would be that you have a Celtic background.  My grandfather was Welsh and he had dark hair and bright blue eyes.\nI've also heard of Indian people having similar characteristics.
663768
all the mistery is in RBG (red blue and green).\nit really depends in conditions.\nif u r really in a dark place u will see black coz non of the 3 cones (red, blue and green) are activated.\nbut, many time blue, green or red color can be seen for a while of closing eye- that may be because of presence of some light which activates specific cones or bleaching of certain cones- bleaching makes u to see a object even though it is not there.\n NOTE: black is actually not a color because we see it when non of the color cones are activated.\nin addition, we see white when all the color cones are activated.\n  i have a lab (PC) activity for u if u want to know how it works. \ngo to:\nhttp://www.exploratorium.edu/exhibits/f_exhibits.html\nchoose the option mix-n-match. u need to download shockwave to run the programme.
667275
Pigments that absorb light rather than reflect it back to the eye "look black". A black pigment can, however, result from a combination of several pigments that collectively absorb all colors. If appropriate proportions of three primary pigments are mixed, the result reflects so little light as to be called "black".\n\nThis provides two superficially opposite but actually complementary descriptions of black. Black is the lack of all colors of light, or an exhaustive combination of multiple colors of pigment. \nIn physics, a black body is a perfect absorber of light, but by a rule derived by Einstein it is also, when heated, the best emitter. Thus, the best radiative cooling, out of sunlight, is by using black paint, though it is important that it be black (a nearly perfect absorber) in the infrared as well.\n\nIn elementary science far Ultraviolet light is called "black light" because, unseen (per se), it causes many minerals and other substances to fluoresce.
555902
They are water droplets. Huge amount of them will be able to partially block sunlight. So, we see them as being black.
334686
My.. Don't you have a textbook for that?\nAnyway, I went to check my O level text book and this is what I got.\nI've written out a not so short description.\nBut you can skip the junk if you only want to know where the rods in our eyes are found.\n\nand the answer is.. \nrods in our eyes are found in the retina, which is the innermost layer of the eyeball.\n\nThere! hope I've helped!\n\n(THE RETINA)\nThe innermost layer of the eyeball is the retina, which is light sensitive. The retina is the layer on which images are formed. It consists of photoreceptors or light-sensitive cells. These are connected to the nerve-endings from the optic nerve. This nerve conveys impulses to the brain when the photoreceptors are stimulated.\nThere are two kinds of photoreceptors: the RODS and the cones.\n\nRODS contain visual purple, the pigment concerned with vision in dim light. Light causes bleaching of visual purple which is involved in light detection. In bright light, all the visual purple is bleached. Thus, when a person enters a dark place from a bright one, he may not be able to distinguish the objects around him for some time. This is because it takes a while for the visual purple to be formed again in the rods.
168933
The shape of the pupils on cats and reptiles are similar because they filter different amounts of light than other organisms.  These organisms are usually nocturnal hunters, though they may be required to move during the day.  Their oblong pupils can be shut down much farther than round ones to block out bright sunlight that might hurt their retinas, and are adapted to open wider at night to allow more light in so that they can see.
95836
Black Colour can be defined as the visual impression experienced in directions from which no VISIBLE LIGHT reaches the eye