That sniper's name is Saito, and while his body is 90% human, he has one eyeball that is 100% mechanical. When it's inactive, it looks like an eyepatch covering the eye, but when he uses it, it flips up to reveal a highly efficient camera lens.
This lens has several augments to it. It can see well over 2 kilometers away. It can be used to apply filters over one's field of vision; for example, Saito uses it to overlay a topographic map in order to estimate slopes from far away. This gives unprecedented depth perception at long range. Sensors within the eye also display wind velocity. Finally, Saito can use satellite connections to lock-on to a target.
