|MadSci Network: Neuroscience|
Your eyes (actually, your photoreceptors) are not "locked" into any given sensitivity when your eyes are closed. The photoreceptors are continually adapting to ambient light conditions, even when your eyes are closed (actually, quite a bit of light can filter through your palpebrae [eyelids] and through your skull, so there's some light available all the time unless you are in a room devoid of light). The only difference between the adaptational state of your photoreceptors with your eyes closed is the additional filtering that your eyelids afford you.
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