Alright, so I went to the local flyshop to get some materials this weekend to tie Barr’s Web wing caddis. First couldn’t find web wing, so I will have to order that. Second, bought some size 12 dry fly hooks but didn’t realize until I got home that they were straight eyes (fortunately that is what the pattern called for…but it was purely an accident).
My question is what does the straight eye do differently than a down-turned eye? Thanks.
I did the same thing not too long ago. I’ve just been bending the eye down a bit before I tie with them. Doesn’t seem to be problematic.
If you dont mind, I’m going to piggy-back that question and also ask, why are upturned hooks common for salmon patterns? What do they do different?
Midge Man - A great question. The responses should prove interesting. Here is a link to a pattern for Barr’s Web Wing Caddis. Note the hook they use.
Tim
I always figured straight eye hooks have a wider gap, and therefore offer a bit more hooking success. Just my thoughts.
I will take a stab.
This will apply only while stripping, but a turned down eye will keep the nose down and the tail up while a turned up eye will keep the nose up and the tail down. This would also depend on how the tippet is tied to the eye as to whether this principle would work. 
Thanks for posting the link to Charlie’s webpage. Hadn’t thought of looking there. It is interesting to note that Charlie has included a step that is not in the magazine’s description which proved troubling. You have to taper the front of the winging material in order to tie it in. That makes much more sense.
I prefer straight eye hooks for dries because I find it easier to keep materials from gumming up the eye while I’m tying. Unless you are tying something like an elk hair caddis, which has material extending out over the hook eye, this works well. The debate over up, down or straight eyes will go on forever but on a size 12 dry fly I don’t think the issue amounts to a hill of beans.
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Thanks for the info folks.
I would think that both upturned and downturned hook eyes are the result of tradition. Passed down from the days when it was necessary to snell a leader/tippet to the hook.
I use straight eye hooks for the majority of my tying, and I’ll take the opposite tack of straightening down eye hooks where possible.
I worked on this very same question a while back. I never came up with the knot explanation, but it’s a good one. Tradition is also a good answer to a lot of it. I also did find out that there is some physics at work. The down-eye of the dry fly hook actually helps it stay up and on the surface. The up-eye of salmon hooks actually works to move the fly down through the water - important when few if any of the salmon patterns use weight. On some flies, like clouser minnows, the straight eye is used rather than a down-eyed streamer. I learned the hard way that when weighting them light, a down-eyed hook (inverted) can actually throw some weight around and cause the fly to ride on it’s side.
Deeky
I have been using straight eyed hook for my Spiders and Flymphs. Roger Fogg in his book ‘A Handbook of North Country Trout Flies’ recommend using them as they come nearest to the old fly hooks tied directly to gut and the fly is in natural continuation of the gut. I like these hooks very much and I don’t think there was any scientific reason for down-eyed hooks except they were convenient for the early manufacturers.
Whatever the theories are about the up or down pull,
I am not convinced, and that is all they are - theories.
Here are a couple of pages on them from my web-site.
http://www.dtnicolson.dial.pipex.com/page54.html
It appears that the folks who make Mustad Hooks think there are specific differences in the hooking ability of a fly relative to the type of eye. But they don’t say what or why, at least as far as I can find.
Link: http://www.mustad.no/abouthooks/anatomy/eye.php
Tim Anderson