There's a change you have astigmatism.

I purchased cheap glasses online and intentionally turned down the astigmatism correction. Significantly reduced eye strain.

* During the day, I use my "correct" prescription. Even though it gives me a bit of eye strain.

* At night, I switch to my adjusted prescription. Not as visibly clear, but significantly less eye strains.

It's nice having a clear separation between "focus" glasses and "relaxing" glasses.