[mrsD]

Since you have been to doctors, I can assume that cataracts have been ruled out?

As we age, the speed of pupil accommodation slows.

I have this now but I am older than you. In effect I have blurring and sometimes fuzzy spells going from far to close focusing even with my trifocals. After a few minutes, it improves. I sense it mostly using my iPhone in bed in the dark. That thing is blinding when the room is dark, even with the brightness turned down.
I also have some glare issues with my monitor so I turn that down too.

Are you taking any other medications that might be affecting your focus? Antihistamines like Benadryl, or other things?

Long term antibiotic therapy can also affect your nutrient status.
You can PM me the name of all the drugs you use and I can look them up for you.
Zinc for example is very important for the retina.
You might spring for Preservision vitamins or Ocuvite.