discussing three major milestones in the development of gunsights, including the introduction of fixed and variable power optical sights, the shift from refractive to prismatic scopes, and the standardization of scope-mounts by the US military.

Discuss three major milestones in the development of gunsights. You can choose from any three of the following, or find other significant innovative milestones in the history of sights from the reading:
· First gunsights
· Introduction of fixed power optical sights
· Introduction of variable power optical sights
· Shift from refractive to prismatic scopes
· Standardization of scope-mounts by the US military
· Introduction of early night-vision optics in WWII