Prism Scope - Astigmatism User-friendly

A prism optic implements a prism to reflect and refract light rather than relying on a conventional lens system. It is like a compact and lightweight version riflescope. 

A prism optic offers a clear and precise image of the target while minimizing the weight and bulk of the optics.

Paragon Prism Scope, Small Size Tells Big.

To see the detailed difference between prism scope and red dot, go check this: prism scope vs. red dot.