Explain why inmates who have been in the dark cell for quite long usually have problems with their eyes and usually squint when in bright light?

No one can see in total darkness. Fortunately, there’s almost always some light available. Even if it’s only dim starlight, that’s enough for your eyes to detect. What’s truly amazing is how little light is required for you to see.

Human eyes have two main features that help us see better in low light: the pupil’s ability to change size, and the eye’s two types of light-sensing cells.

Opening up to let in more light

Your pupils are the black areas at the front of your eyes that let light enter. They look black because the light that reaches them is absorbed inside the eyeball. It’s then converted by your brain into your perceptions of the world.

You’ve probably noticed that pupils can change size in response to light. Outside on a bright sunny day, your pupils become very small. This lets less light into the eye since there’s plenty available