Hi, I am new to this site and hope you can help and bear with me! (Smile, please). After shutting bedroom lights at night, how do our eyes adjust, and, how is our hearing heightened, please?

Question

Hi, I am new to this site and hope you can help and bear with me!   (Smile, please).  After shutting bedroom lights at night, how do our eyes adjust, and, how is our hearing heightened, please?

anonymous · Answer

Night listening can heighten your sense of hearing. You'll focus your hearing sense better due to your sight limitations. It's not that your sense of hearing is improving suddenly, it's that you are concentrating on what you can hear more than you would normally. Your heightened *concentration* on sounds will make it as though you are hearing better than before. 

It's like having a cursory glance at something in the horizon (and not seeing it) and squinting at it (so you do see that speck). It's all about concentration.

anonymous · Answer

The pupil size of the eye is controlled by muscles in the iris, the coloured part of the eye. The purpose of this is to control the amount of light hitting the light-sensitive retina, at the back of the eye. Too much light can damage the retina and too little would mean that you couldn't see properly. That is why the pupil shrinks in bright light, and expands in low light.