so you take a perfectly good handgun and file down the front site - you know its worth zero after that ? So what will the new owner that can actually shoot do when he gets it?
your not sighting in a military rifle to adjust for individual "eyesight", your adjusting the weapon to be accurate - an individuals weapon can be adjusted on the bench if it needs to be - I often take a pickup load of AKs to the range with my good shooters and adjust the whole units weapons en mass . The ak front site alignment tools are far and few between and I hat the gaggle fxxk of going through BZO with new soldiers. Once its zero'd we work on fundamentals and everyone qualifies with that weapon - never had a problem with that
the sites shouldn't line up any different in a bench or in your hands - and no - at 25 meters its point of aim point of impact for all commercial rounds.
if your consistently missing the X or the black or whatever your doing something wrong - that needs to be corrected before you go filing down front sights - thats insane.
all im saying is if the gun shoots accurately you need to adjust your shooting - not the gun.
any problem can be fixed by a competent instructor - you should invest the money you lose on the guns value on a couple sessions with an instructor that knows what they are doing
and no - its not geometry the same points line up the same for everyone if they are using their fundamentals. Do you think the military of the world adjust accurate guns to compensate for poor shooters? No they train them to shoot correctly - I dont know what constitutes a "sweet spot" on an eye but the "geometry" would only adjust for the diameter if the width of the pupil (a fully dilated pupil at most)