I've finally settled on 2 diopter for my iron sight shooting which, strangely enough, is less than my 3 diopter prescription for distance. This assumes the lighting conditions close down my pupil. Even cheap 2D safety glasses work just fine, but I'd like to find a lens color with a lower transmission that enhances target contrast for use in really bright days. Shooting steel challenge in Idaho the targets are white and the backdrop a light sandy soil which unfortunately isn't that far from white. I'm currently using yellow lenses as well and while these don't degrade the contrast they don't enhance the white versus background; one possibility would be yellow lenses with, for example, 50% transmission. So I'm look at a 2D right eye in clear and a 2D right eye in a TBD color/transmission for the brightest conditions. Maybe a neutral gray for the high brightness given the poor inherent color contrast between target and background? Anyone care to weigh in? FWIW I don't even need a prescription in my post-cataract surgery left eye with 20/15 and only 1D of cylinder so life ain't all that bad.