I hope this isn't too dumb of a question but here goes...

In researching the types of flies I might need for my trip to Washington later this summer I have noticed that some of the streamer patterns are tied on hooks with up-turned eyes, some are on hooks with down-turned eyes and others are tied on hooks with straight eyes.

Does this relate to the type of fly? When I get around to tying some flies myself does it really matter too much which type of hook I use? What do any of you recommend? Thanks.

Royce