I suffer from common migraines. Started taking Topiramate 10 days ago to prevent them. I wear contacts - prescription +5.25. 2 days ago, vision very blurry. Took lenses out and vision actually better without them. Got an emergency appt with Optician yesterday who said my prescription has dramatically changed to +3.25. Did a thorough check and said eyes in perfect health, no cataracts, glucoma etc. Need to make an appt with GP to check blood sugar level immediately. I have no symptoms of diabetes. Only other symptoms I have are tingling in soles of feet and quite a bit of light headed-ness this week. Seems to tie in with the new tablets. Am female, 43, just under 11 stone and exercise regularly. Otherwise, I'm very healthy. Obviously, I'm very concerned over sudden change in my eyesight. Oh, by the way, I'm back wearing my lenses today, so obviously my prescription has changed again!