Question

Can anyone explain the 'green flash right after sunset' phenomenon?

Answer 1

This would probably be better handled in a physics/planetary science forum...
But, the basics are that it's an optical mirrage caused by a few different reasons,
ie: Surface warmer than the overlying air; Atmospheric inversion layer below eye level; surface colder than air... and others.

Answer 2

I thought it was simply something about the eyes being exposed to light and stuff, the same 'green' colorscheme effect you get when you stare at a light and then turn away