Mine do that all the time too and they are scared of everything. Turning off the light seems to help but my light isnt very bright anyway. Its a single 48" bulb for a 100 gallon tank
How long have you had them? I think it might be normal for new fish to hide for the first couple days, maybe even weeks. If they're new though have no fear, pretty soon they should be out acting like they own the tank.
ususally i get my fish used to me by feeding only when i turn on the light ...that way they will move with the light on ...after about two weeks as soon as they see the light they all start circiling for food ....
I've had them forever and they used to be out all of the time, but all of a sudden they hide. I have not gotten any new scary fish or anything either. but than i transfered them into a 75g w/ the rest of my fish and they still hide but I'll give it time, they sure do come out at feeding time though!
Dollars are pretty skittish fish. Move quickly or anything and they'll go running for cover. That behavior had me frustrated to the point where I was about to take them to the LFS to get rid of them. Now I'm glad I didn't. They're a perfect companion for my angels. Sure they run and hide when you make a sudden move, but sit still for a few minutes and they'll come back out and play.