Injected lenses provide less peripheral distortion than stamped lenses. Stamped have the same thickness throughout the entire lens, which means at the edges, where the lens curves, you are looking through more material, which distorts vision. An injected lens can vary the thickness of the lens towards the outer edges, providing a more uniform thickness and undistorted peripheral vision. All anon. goggles use injected lenses.
(lens, injected, stamped)