Getting the eye to stick
The eye has an adhesive backing, but thats not enough to make it stick through repeated casting, wetting and hopefully a fish or two.
I apply the eye then coat about 1/2 to 1/3 of the front of the eye and the finished head with either epoxy or Loon Hard Head. I try not to use to much because it adds un needed weight to the fly.
In this image you can see the edge of the Hard Head at just about the front edge of the pupil of the eye.