When dark adapted, you can see only in black and white (no color). If there is no light at all – say in a deep cave – you cannot see anything. A few animals have infrared “vision”, which works by detecting heat. Heat produces infrared radiation, which is invisible to the human eye.
When it comes to seeing in the dark, traditional belief is that humans are not able to. However, new research has challenged this, suggesting that at least 50% of all people are able to see the movement of their own hand, even in an environment that is pitch black.
If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still occurs if you are not in complete darkness.
Eigengrau (German for "intrinsic gray"; pronounced [ˈʔaɪ̯gŋ̍ˌgʁaʊ̯]), also called Eigenlicht (Dutch and German for "intrinsic light"), dark light, or brain gray, is the uniform dark gray background color that many people report seeing in the absence of light.
Cats and dogs can see in the pitch dark
Their eyes have a high density of rods, which are the cells that are sensitive to dim light. This means they can see normally with as little as 15% of light that humans would need.
First of all, it is impossible to see anything at all in total darkness. Total darkness means the absence of light, and our eyes depend on light to see. With that said, it is quite rare to be in a situation with total darkness, even at night.
Humans (and most animals) can see in the “dark” only if there is some starlight or, better, moonlight. It takes some time (10 to 30 minutes) for your eyes to become dark adapted to see in such low-light conditions.
No. Night vision devices work by amplifying the available light in a given area, so if there's absolutely no light to amplify, then your night vision device turns into an expensive blindfold.
While they can still get around better than humans in total darkness due to their other senses, they will not be able to see. Although it's rare to have complete darkness, it's helpful to turn on a nightlight so your dog can see better at night.
If a place or the night is pitch-black, it is completely dark.
Most people see splashes of colors and flashes of light on a not-quite-jet-black background when their eyes are closed. It's a phenomenon called phosphene, and it boils down to this: Our visual system — eyes and brains — don't shut off when denied light.
This phenomenon is known as "dark adaptation," and it typically takes between 20 and 30 minutes to reach its maximum, depending on the intensity of light exposure in the previous surroundings.
Keep one eye fully shut, and use the other for finding that item in the backpack with the flashlight on. Now, after you turn off the flashlight, open the closed eye, and close the open one. You will be able to see much better in the dark with the previously closed eye that was not exposed to light.
Psychology textbooks state that on a clear, dark night, a candle flame can be spotted from as far away as 48 kilometres. The night sky, with its dark background pricked by stars, offers some startling examples of long-distance vision. Stars are huge; many we see in the night sky are millions of kilometres in diameter.
Objects which are black in colour will absorb all the light which is falling on them and will reflect none. Hence, no light reaches our eye and the objects appear black.
Both rods and cones are sensitive to light. The difference between them is that the rods allow us to see in very dim light but don't permit detection of color, while the cones let us see color but they don't work in dim light. When it gets dark the cones lose their ability to respond to light.
Horses have excellent night vision. Horse eyes are large, they have a large pupil, and this allows ample amount of light to enter even in dark situations. On a night lit by a partial moon or stars, horses can see just as well as people can in full daylight.
Scientists have discovered the receptors that allow snakes to find prey in the dark. Snakes can 'see' in the dark thanks to protein channels that are activated by heat from the bodies of their prey.
Birds can see at night but some species have better night vision than others. Nocturnal birds such as owls have amazing night vision that allows them to fly around and hunt for food in the night. It is believed though, that birds aren't able to see in total darkness.
Sharks also have the ability to see well in the dark because of a layer of mirrored crystals behind their retina called tapetum lucidum. It reflects light giving them a second chance to see the image as it goes through the retina again.
Infrared cameras are equipped with two necessary components: LED lights that emit infrared light, which is invisible to the human eye, and an image sensor that can see infrared light. The LED lights illuminate the camera's surroundings for the image sensor, which then creates black-and-white, night vision images.
Night Vision
When a camera tries to see in the dark, it needs a light source to illuminate the area below it. Unfortunately, the night vision illuminators that come with consumer cameras are designed for short range only and are of a fixed brightness.
One of the best ways to help your eyes learn to see in the dark is to let your eyes slowly and naturally adjust to low light. The best way to do this is by sitting in complete darkness for at least 20 minutes before going out at night. You can also cover your eyes or use a sleep mask to help aid this practice.
The bottom line is: without light, there would be no sight. The visual ability of humans and other animals is the result of the complex interaction of light, eyes and brain. We are able to see because light from an object can move through space and reach our eyes.
People who have lost their vision have a wide range of reactions. Some people have described experiencing pure darkness as if they were in a cave. Some see flashes or have strong visual illusions, for example, familiar forms, shapes, and colors, or lights.