I went my optometrist and had him tweak my prescription until i could see 1/2 inch holes in targets 25 yards away clearly. I always shoot target focused, so my sights always appear moderately blurry, especially since I've started shooting right handed flintlocks as a lefty. The flash doesn't bother me, but if I don't close my right eye, the falling of the hammer in front of that eye causes me to flinch downward as the hammer falls.