If your eyes are fighting each other...
right handed..right dominant eye
Go to a store and buy a roll of the frosted scotch tape and put it over the non dominant left eye lens.
The peephole will give you better definition of the sights. It works like a camera lens that you close down the aperture so that the far and near stuff is all in focus and not blurred.
If you have 20/20 vison you will probably be okay with the scotch tape trick.
Have a nice day at the range
NRA Life Member