Ok, so this week is sort of a cheat for me as these are iron sights and not an optic.
I’ve found that people unfamiliar with the AK tend to be surprised at how narrow the rear notch is. AK sights can be quite fast to use if you are used to them, but I have seen novices struggle to line them up. It is not uncommon to see AK owners here in the states widen the rear notch.
The AK rear sight is adjustable for distance.
You zero by adjusting the front sight. It is adjustable for elevation and windage.
You will need a tool to adjust AK sights. Adjusting elevation requires rotating the front sight post. 1 full turn of the front sight post is about 8 MOA. You could turn the front sight post with needle nose pliers, but it would be better to use a tool made for it.
Windage is adjusted by pushing the rear sight drum. This is a friction fit in the front sight base and can be a real pain to adjust. You might be able to get it to move with a hammer and punch, but it is preferable to use a sight pusher. It is also not uncommon to hear about cheap sight pushing breaking on AK or SKS sights.
I use the Magna-Matic sight tool, it is the best one that I know of. While not obvious, the top of the tool is cut to go over the front sight post for adjusting elevation. The O design instead of a C shaped design helps prevent it from slipping off the sight or breaking while it is in use.
How much windage adjustment you get per turn of sight pusher will depend on what thread pitch the sight pusher uses. Rule of thumb is that it will be approximately 1 MOA per 1/10 a turn of the sight pusher.
It is very common for AK sights to be canted, and for them to require excessive windage adjustments to zero, such as this Arsenal AK pictured above.
Some AKs use the “RPK” rear sight. This has a windage adjustment built into it. The knob on the right side of the rear sight is spring loaded and can be pulled away from the sight and rotated to adjust windage. I have no clue how much adjustment per click, but they are very easy to use.
There is also a rare rear sight for suppressed AKs that has a cam for switching between different ammunition.
AK have simple and effective sights, but sometimes they can be a real pain in the ass to get zeroed.