My eyes are also more sensitive than those of most people I know. For a large portion of my life I've been able to walk around the house in the middle of the night with no lights on and be able to see where I'm going.
As for the one eye thing, I also do that in bright light, but always with my right eye, which is my bad eye. Squinting is also a common thing to do when you can't quite focus on something, so if you haven't already done so, I'd suggest making a visit to the optometrist, kiki3, PLA. 
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Yesterday is time spent,
Tomorrow is Hope's rent,
But Today is a gift,
And that's why it's called The Present.