Is it likely for SPH measurement on eye test to change from 0.50 to 1.75 in a 6 !
Question: Or is it more likely that the optician has made a mistake?
Answers: Or is it more likely that the optician has made a mistake?
This sounds normal.
I personally would never have an eye examination abroad. Their "opticians" are often nowhere near as qualified as in the UK. They sometimes prescribe from auto-refractor (the machine where you look at a picture and it comes in and out of focus) results, which in the UK we only use it as a guide to base our prescriptions on.
It's in your best interest to always use the same optician as if any changes occur it is easier (an sometimes only possible) to detect if the optician has seen you before.
Yes it is possible. If in doubt, do check the eye sight again with another opticans
Possible, but could be indicative of another problem. Regardless of your age you should be checked for diabetes even if you think your healthy. I'm not sure how old you are but a cataract is also possible. Did both eyes change? How old are you?