2006-09-24 07:22:32 · 14 answers · asked by Kristi J 1 in Science & Mathematics ➔ Biology
The human eye uses light to see. Light bounces off our surroundings and into our eye through our pupil, the black hole at the center. A picture forms on our retina, the lining at the back of the eye. Our brain makes sense out of what we see. Without light, there is nothing to enter our retina and therefore we can not see in dark.
2006-09-24 07:24:53 · answer #1 · answered by Chelle 2 · 2⤊ 0⤋
Because our eyes can only detect wavelengths in the visible light spectrum. Wave radiation occurs as energy is released from, reflected off, or transmitted through an object. Light bulb releases wave energy, a red ball will absorb all wavelengths but reflect red, a green lens will absorb all wave lengths but green and transmit it through and out the other side.
"Visible light" is by definition, those wavelengths the human eye can detect.
So, in the absence of a source of visable light, our eyes cannot detect anything. At very low levels, our eyes cannot detect anything. With other species it is different. The structure of cat's eyes are such that they can detect lower levels of wave energy, and as such "see in the dark." It's dark for us, not them.
Often, there is energy about, not in our visible spectrum, that is visible to other creatures.
Some night predators, have eyes more sensitive in the infrared region, (below our eye's ability to detect). They rely more on "seeing" the body heat of prey. In the day, with so much heat, they lose their advantage to creatures of the day that see more in the visible spectrum--they hide and sleep during the day.
2006-09-24 08:04:39 · answer #2 · answered by mt_hopper 3 · 1⤊ 0⤋
It's because you see objects when light reflected from them falls on a portion of your eye called the retina.Then there will be signals sent to the brain about that and you'll be able to see.So without light,it's impossible.Even a camera works on this principle.when light falls on the film,the sensitive coating on it deforms in the pattern of the objects' features.When washed in certain solutions,you get the picture.So, it's not possible to take pictures in the dark without a flash.
2006-09-24 07:39:12 · answer #3 · answered by pavan 1 · 1⤊ 0⤋
The rods and cones, sensitive cells in the eye that allow us to see, are aroused and activated by light. One can see "in the dark" if there is some light, even fairly dim light. With no light at all, there is nothing to trigger the eye to work, so to speak.
2006-09-24 07:27:07 · answer #4 · answered by Anonymous · 1⤊ 0⤋
The inside of our eyes have microscopic cells which are either "rods" of "cones". Rods are cells that absorb light to be able to see objects projected through the lens. Cones help to distinguish between the different colours. Animals such as owls and cats have many more rods than cones in their eyes, that's why they can see so well in darkness. Human eyes have more cones then rods, that's why we can see in colour, while most other animals can only see in black and white. You owe me 10 points please :-)
2006-09-24 07:32:29 · answer #5 · answered by kittykins 6 · 1⤊ 0⤋
We can't see in the dark because there isn't any light and that is crucial to sight.
2006-09-24 07:34:28 · answer #6 · answered by I shan't say. 1 · 0⤊ 1⤋
I was hit by lightning and I can see in the dark.
2006-09-24 07:27:21 · answer #7 · answered by Isis 7 · 0⤊ 1⤋
Because there is no light to reflect from the retina of the eye.
2006-09-24 07:35:12 · answer #8 · answered by THE UNKNOWN 5 · 0⤊ 0⤋
the light source is to low to be reflected back to our eyes
2006-09-24 07:26:49 · answer #9 · answered by gussie r 3 · 0⤊ 1⤋
the eye is like a projection
If there's no light nothing can be projected into our eyes
2006-09-24 07:25:33 · answer #10 · answered by Anonymous · 0⤊ 1⤋