Why the "except on handguns" remark? Having red dots on a SigP320, Glock 19X, Dan Wesson 9mm 1911 and Sig P365XL, they help in both accuracy and shorten time for first shot. Battery life is about 1 year with daily carry and work even in sun light. They should be standard on all handguns today.I'm a believer in red dot sights. I have mounted red dots on most of my rifles. I have presbyopia also, but I don't have a problem shooting with iron sights as long as I'm wearing my glasses. Red dots are great as long as you don't have a bad astigmatism. I would use the red dots even if I had 20/20 vision, except on hand guns.