Scotopic vision in humans is what describes human vision in low light conditions, primarily using the rods in the retina.
Scotopic vision in humans allows us to see in dim light, in which the cone cells that are responsible for color vision are not active.
The characteristics of Scotopic vision are low visual acuity or blurriness and a lack of color perception.
Humans cannot have total natural night vision although humans can adapt to low light conditions and see some in low light conditions but not total darkness.
Us humans don't possess any true night vision in the way some nocturnal animals do.
Human eyes rely on both cone cells and rod cells to see and the eyes also rely on light entering the eye to allow us to see.
The reason why some people can seek in the dark at least some is due to genetics, eye color and the sensitivity of their rod cells.
Nobody can actually see fully or truly in total darkness like they can in the day but some people can see some in total dark.
The human eye contains two types of photoreceptor cells, which are cones that are responsible for color vision in bright light and also rods which are also more sensitive to light and are also crucial for seeing in dim light conditions.
The light gets into the human eyes through the pupils in the irises and in darker light, the pupils get bigger.
A person cannot see in complete darkness.
Human eyesight relies on the light reflecting off of objects and then entering of the eye.
And in total darkness the eyes are not able to detect anything as no light is entering the eye.
Humans can adapt to low light conditions but us humans all require some form of light to see, even if it's just a small amount of light to see a little bit.
Human eyes contain rods and cones which are specialized cells that detect light.
The rods of the eyes are responsible for vision in low light conditions and the cones in the eyes are responsible for color vision as well as detail in brighter light conditions.
And in total darkness, there is no light that is being reflected or emitted, so there is nothing for the eyes to detect so we cannot see.
Also the pupils of our eyes also dilate or widen to let in more light in darker conditions, although this only works if there is at least some amount of light to gather.
And although the human brain can sometimes predict what may be happening based on any past experiences such as seeing our hands move in darkness, it's not true sight and it does not work in complete darkness.
Nocturnal animals can see in the dark and low light conditions as they have evolved special adaptations in their eyes so they can see effectively in low light conditions.
Nocturnal animals have a larger number of rod cells which are sensitive to light and motion when compared to cone cells that are responsible for color vision and also require bright light.
And many nocturnal animals also have a reflective layer called tapetum lucidum which is behind the retina, and this tapetum lucidum bounces light back through the retina and gives it a second change to detect light.
And some nocturnal animals also have eyes which are larger and have wider pupils that can also possess a slit shaped pupil for better light control.
Us humans don't have these adaptations so we cannot see very good in low light conditions and cannot see in total or complete darkness.