A sniper should have sharp / good eyeslight for obvious reasons. As mentioned in my previous post, i have not seen or heard of a sniper who are "4 eyes" during my NSF and reservist as a sniper pc.
Practical examples why a SAF sniper cann't / shouldn't wear glasses:-
1. If one does not handle / hold the T-bolt rifle properly during firing, one may suffer a "sniper eye injury", term we use in sniper community in saf (not sure about other countries). Basically, the recoil from firing is so strong that the scope of the rifle hits the shooter's eye causing "blue black". Hmmm imagine what will happen to a "4 eye" shooter glasses.
2. Depending on the situation, a sniper may need to dig a "sniper trench" and stay in the trench for hours if not days. The "hole" is so humid that the len on rifle's scope, bino and spotter will fog up. Surely a "4 eye" shooter will face serious problems in such situtaion.
3. One needs to have a good judgement of distances.
Of course one may argue that he can wear contact lenses
