[soylentcola]

I'd imagine it's also less noticeable in scenarios when you don't need to read smaller letters from a distance as much (ie: when you are playing outside rather than sitting in class).

[throwawayboise]

Also in bright light your pupils are constricted so depth of field is greater. In dim light your pupils are dialated and depth of field is shallower. Same principle as a camera lens f-stop.

So the perception that you see more clearly in bright outdoor conditions could be true.