Bad luck with mine. - Holosun HM3X 3x Red Dot Sight Magnifier

Good eye relief and the clarity was fine for the price, until two large black flakes appeared on different strata of the internal lenses--enough to blur the view at the center. Not subjected to any severe recoil or rough handling, maybe 1k rounds of 5.56 from a bench before the issue became apparent.

I have a few Holosun red dots that have performed well, and bought this unit at a local shop where it compared favorably to Aimpoint and Eotech models apart from durability.