Bats are not blind ....most can see as well as us!
They hunt at night as there is less predators and their prey are out in abundance.
But if forced due to really bad weather when flying is unable at night and no beasties out at night for a few nights they may take advantage of a break in the weather during the day to up their body weight/fat espesh if they have young to feed!
Dawn n Dusk are the best times to see bats ...but on overcast days the times can stretch out as it is dull before proper dusk and dawn can be delayed so you can see them for longer!
Life is too short to spend it in beige underwear!