Was issued my first Garand in the mid 50's, shot them in unit competitions for 7 years or so and a year on post AMU. Upon separation, shot personal M1 in civilian service rifle matches until I could no longer see the front sight then retired the Garand and switched to bolt guns which allowed a front aperture sight. With a Merit adjustible rear aperture sight (
http://meritcorporation.com/) and the proper sized front aperture sight (shooting bullseye targets), shot the bolt guns in NRA cross the course matches (200-600 yds.) until I finally made high master at age 63, in spite of declining eyesight. Did do a lot of glasses changes toward the end, but where there is a will, there is a way. Wish I had hear of the stick on bifocal lenses back then.
Iron sights w/declining eyesight are fine on targets, but hunting game, not so much. As has been alluded to, aperture sights require good light, not always present in prime hunting time.
A few things I learned over the years.
1) Sight alignment is more critical than sight picture. An error is sight alignment error grows as range increases. Sight picture is what it is.
2) Sharp front sight is most important part of the equation.
3) Adjust rear sight aperture to focus vision on front sight.
4) Smallest front aperture front (which allows sufficient light) will sharpen image of target. A greying out of target calls for larger aperture.
5) Rule changes late in my shooting "career" allowed for a single corrective lens in either the front or rear sight. I chose to place the lens in rear sight, choosing the power based on light availability and to focus on the front sight.
At age 64 arthritis set in and I switched to coyote hunting/scoped rifles, which brings me back to the quote above. . Again, where there is a will, there is a way.
Devised a no-drill base, which replaced the rear sight on my M1. Took three tries, but finally found the right optic and after a number of years of forced retirement managed to get the old girl out of the safe.. A recap of that journey:
First mounted a FFII, which worked, but the red dot was a bit too large and beginning cataracts cause a starburst instead of a round dot. Better than irons, but still not quite target quality. A bit of scrounging in my junk box turned up a Millett red dot sight. Hmm, it would fit and not interfere w/clip loading/ejection
.
Clean red dot helped accuracy, but my 80 YO eyes at the time still needed some help. If only someone made a compact red dot w/a little magnification.
A year or so went by and I discovered the Primary Arms 3x compact scope and the Garand graduated from plinking to some serious paper punching to predator rifle in one fell swoop.
The 125 gr. NBT has the trajectory of a .270 and hammered this coyote @ 175 yds.
Had cataract surgery a couple of years ago and, lo and behold, can see iron sights reasonably well again, but not as well as w/optical assistance. Always chose the scopes for hunting due to superior light gathering ability in poor light.
One more tip, the target size/shape is all important to shooting those tiny groups. Experiment and find the best size/shape of target for your optic.