I am on the wrong side of 50. My eyes can still shoot irons but not as well as dots. If you are shooting them for some for of serious purpose - competition, self defense or other antisocial application - you need to train the transition to dots. Most LEOs go through a multi day training for dot adoption. I would also saying it presents some challenges to go from one to another. My sight line and head position shooting a glock with irons is generally lower than with a dot on it. Particualarly the SRO i use in USPSA.