 Hook eye design is usually optimized for either strength, weight and/or presentation.There are different types of eyes to the hooks.Typical eye types include the ring or ball eye, a brazed eye-the eye is fully closed, a tapered eye to reduce weight, a looped eye—traditional on Atlantic Salmon flies, needle eyes, and spade end—no eye at all, but a flattened area to allow secure snelling of the leader to the hook.