Currently, if your eyes are closed you can still get a sense of the light around you, and moving your head around you can tell if you’re moving it toward or away from a light source (barring maybe if you’re outdoors and it’s bright out all around you).
But what if when we closed our eyes it was like full blackout? Would blinking become disorienting? Could it mess up circadian rhythms? Something else? Or would it not really matter?
Sure but I need help going to (and staying) sleep, not waking up. My natural wake up time is before the sun rises (430-5am)
Have you tried abusing prescription drugs?
Interestingly, you note that your natural wake up time is when the sun rises, but don’t recognize that it might be because that’s when the sun rises.
Interestingly, I wake up 2 hours before sunrise and noted my use of blackout curtains regardless.
Sounds like you have a relatively healthy sleep-wake schedule.