Yes, you would see a glow from the back of your eyelids when your eyes were closed.
The perception of the color or darkness behind closed eyelids can vary among individuals, but it's generally described as dark or black rather than gray. When your eyes are closed and not exposed to light, the absence of visual stimuli often leads to a perception of darkness. The exact shade can depend on factors such as ambient light in the environment and individual variations in perception.
Light still travels through our eyelids. They are somewhat transparent.
Because their eyes are sensitive to the light, so they keep their eyelids closed, but that's not always the case.
Our eyelids do block stimuli (light) from entering our eyes, but they can't do it completely. That's why when we are facing the sun or a light with our eyes closed we seem to see some color/colors So yes, we can see through our eyelids, a little. However, during sleep, our eyes are actually shut off temporarily by our brains. The main reason our eyes close for sleep is so that they do not dry out.
Well you do see when you close your eyes, just that your eyelids block near enough all the light so you cant see yet you can, if that makes sense...
A human eyelid is not transparent of course. But some animals like snakes have permanently sealed transparent eyelids which protect their eyes from foreign materials. Frogs also have transparent eyelids to protect its eyes while swimming in water.
Human eyes begin to develop about 22 days after fertilization! Between weeks 10-12, the eyelids are formed, and are closed; they remain closed until week 27-28, when the fetus can open and close the eyelids. So, the fetus (unborn baby) can see, though it's pretty dark inside there! When they're born, babies can see light and movement, but they can't focus on anything or follow movement with their eyes.
Closed.
Simple reflex
Yes, they are not like ours though. Parakeet eyelids are hidden in their heads (sorta) They are very thick so the light doen't get through as well. But if you keep a light on all night near the bird, it won't be able to sleep.
The light bulb is a closed system: no mass transfer.
when a light is on it is part of a scolde circuit