Any tips/tricks for centering the apex?

[Mmm390]

So Ive noticed the grind lines on one of my blades are uneven...causing the apex of the edge to slightly favor one side. I'm having a hard time getting a good look at progress I've made. So I'm probably going to get a jewelry loop.
Is there any other tips/tricks that might help me out ?

Thanks!

 

[Sergeua]

You can dull the edge so it reflect light back and will be easier to see what's going on.