Redneck:

An interesting question. Like you I have a bunch of eyes in stock. I used some of them to tie a fly called Alexandra. It calls for peacock sword but the eye didn't look too bad. I don't think they are a sturdy as the regular herl or the sword.

I went to google and typed the words "peacock eye fly" in their search window and found several patterns which I have not tried.

I hope others will give you more info on this as I have a bunch of eyes.

Tim