Poor Diagnosis

Over the last 10 years or so, I have been using Spec Savers. I have decided to never go back and rather revert to using an independent optometrist. According to Spec Savers I have gone from far sighted to shorted sighted (acceptable) and then looked at like I'm daft for coming in for an eye test because apparently I have perfect vision. How does one go from far to near sighted to perfect vision? Yet here I sit, struggling to see and read. The worst part is that every time you go there is a new optometrist and you never get the same answer twice. It's like they're chosen out of lucky dips and have no idea what they are really doing. I will never go back.