Salmon hooks vs regular stright eye hooks

[ruge13]

This may be a stupid question, but can someone tell me the difference or significance of using the upturned Salmon hooks vs. a straight eye? Is there a spacific reason they are turned up? Is it just tradition? Does it effect the way the fly moves/acts or change the strength or porperties of the hooks at all? Can you tell I know nothing about them?

[scruffy_fish]

Shaun,
Since no one has offered up any answers to your question, I'll make an attempt.
In the art of hook making there was a time that makers could not produce an eye on a hook. Flies in that time period were tied with a gut material loop tied in, aka: traditional gut eye salmon flies.
As hook making developed a loop (wire bent back on itself) was made in the wire to form and attachment location. The wire loop was seen as a problem because the leader was able to shift position when presenting the fly in heavy current.
The design was altered, to bend the loop up and out of the way, so the leader could be tied in through the loop and secured to the head of the fly. A turle knot was used with the loop as a stop for attaching the fly to the leader. This allowed the fly to swim in control with a straight pull and connection to the fly.
Fly control is key in salmon fishing, as in all fly fishing....

[James Warren]

It really is all about control of the fly. In salmon (and steelhead) fishing, it is of the upmost importance to keep the fly "swimming" on a profile. The to goal is for the fish to always see the fly broadside as it swings through the run. Most fish (the Atlantic salmon I have caught anyway) will follow a fly through the lie and eat just as the swing in complete directly downstream from you. The turle knot is great for this control. Another way to fish that was very popular for some time was know as Greased Line Fishing. In this method the upturned eye is critical for a riffling hitch knot. Blah, blah, blah. The eye does help but also looks pretty neat too. I have started using up-eyes dry fly hooks for everything accept parachutes as I believe it keeps the knot off the water, and does not hamper the view of the fly from below. Just my 2 cents