Almost all of us would have seen 007 James Bond in action during nights wearing High-tech NIGHT VISION GLASSES.He just needs to push an on button and he could see clearly during nights,but their's a lot of stuff happening inside it including the one which gave Albert Einstein his Nobel Price!
We'll get into it in a moment but first we should have a look at human eye to make it more clear...
So here's diagram of human eye.It could be compared to a projector and screen.Our eye also has a projector opening called Pupil and Retina acts as the screen.Pupil has a special function which enables it to widen up when the surrounding is dark and narrows down when hit by bright light.This is done to prevent Retina from getting damaged(as we all know eye is a very sensitive organ).
Now at the time of dark pupil widens up but their is no light found near surrounding area.
No light=less photons(we cannot say no photons...)so a Night Vision Glass enables in converting photons to electron.(this process was first found by Albert Einstein termed as Photoelectric effect)Photoelectric effect is effect seen when a photon hits some metal surface(in this case Photo Cathode),their is ejection of electrons.Then electrons are amplified(increased in number) using a Micro-channel Plate.Then again these multiplied electrons are converted to photons(since are eyes can't see electrons) by a Phosphor Screen.And we get a clarified Image.Who would have thought that a simple push-on button makes this much stuff happen...
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