Hello and welcome to HCM.
Thanks for your query.
Shifting from prescribed glasses to lenses does take some getting used to and the symptoms you are experiencing could clearly be because of this. But, we will have to rule out all other conditions before reaching this conclusion.
The presentation you have described could relate to migraine headaches
as well. A few other symptoms of this condition are headache on one side of the head, difficulty in concentrating on something (visually), irritation from light and sound, etc.
You could also try to rest your eyes by taking breaks during work and during these breaks, avoid straining your eyes.
I hope this information helps. You could write back to me for any further clarifications.