So I was standing outside, waiting for the train. I was tired so I closed my eyes for a while. Then when I opened them, the world was a lot more blue than it normally is - why is this? I tried it a couple more times to be sure that it wasn't just a mistake, which confirmed it, as the world kept being blue (of course, not permanent, it slowly gets back to the "normal" colors).

I'd appreciate a simple explanation, as I'm not a biology or physics student. I only have a very basic understanding of both subjects. Thanks in advance!

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    $\begingroup$ When your eyes are closed in bright light, you see red because the light shines through the blood vessels inside your eyelids. Eventually this will "wear out" your red cone cells so that they stop sending signals to the brain (a form of sensory adaptation). This results in you only seeing blue and green for a few minutes after opening your eyes until your red cone cells are able to recover and begin firing again. I am not sure why this question is on hold, it seems like a good question to me. Maybe I missed something... $\endgroup$ – CDB Feb 11 '16 at 21:44
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    $\begingroup$ I also don't really know why it's being closed. It says opinion-based, but I don't really find where I put in my opinion. However, this is my first question on this forum, so I guess I'm not familiar with your customs. Thanks for the reply though, you answered my question! $\endgroup$ – vrugtehagel Feb 11 '16 at 22:16
  • $\begingroup$ My pleasure. :) $\endgroup$ – CDB Feb 12 '16 at 17:12
  • $\begingroup$ Initially I also not clearly thought-out what could had happened. But after reading the clear-cut answer by user @CDB, I couldn't think the answer as 'opinion-based' from any viewpoint. It was an 'objective' answer. $\endgroup$ – Always Confused Sep 17 '16 at 15:56
  • $\begingroup$ @CDB your answer's flavor was like a detective story, than many-other types of scientific q/a. $\endgroup$ – Always Confused Sep 17 '16 at 15:59

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