I had a similar problem, initialy started with a 2.0 cyl then over time and going thru the ground school i started wearing glasses more and more.
Mainly because i couldn't deal with the diffrence between glasses on then off.
After three or so years my eyes got worse until they reached 3.0 cyl and I couldn't live without glasses for anything. So trundled off to a laser sugery chap and got the eyes blasted and very happy with the result and threw the glasses out!
I suspect in your case you may need time to adjust initialy. But it is also possible that perhaps the amount of correction givenmay be too much for your brain to tolerate. If so get back to the optician explain the problem and ask for less of a coreection.
Best of luck