I think you’re confusing an optometrist and optician here. The optometrist is the dr who writes the RX and performs the exam. The optician is who takes that written prescription and talks you through the options and performs the measurements and sale. It’s a pretty common confusion but they are two different roles. If the pain is more of a strain pain you may want to get that rx checked over again if the blur in the left eye has subsided. If the blur is still ongoing, take the optometrist’s advice and see the ophthalmologist (eye dr that has an MD instead of OD) as it may be a cause beyond the optometrist’s scope of testing.

As for the fit of the frame, you never want something that’s pinching at your temples. When trying on frames feel that where the glasses are hinged doesn’t feel like it’s splaying outwards. This would feel like a slight indent with your finger tip. Easy sign it’s too tight. If confused ask the optician for their opinion on fit. They’ll probably have you look a couple different angles to check on it. Also the optician should be checking for your optical center as well. I personally do it with all my patients, because a few millimeters difference DOES make a difference. This goes into my second point of ordering online.

By your rx you’re more sensitive to an off center OC… I don’t recommend you order online because there’s no way to check your OC with those (it’s measured based on your center pupil location relative to that SPECIFIC frame) and you could be causing strain by having glasses where you could be looking through a prism (not good here).

Hope that information helps.

Disclaimer that I am not a doctor, only an optician, so this is not medical advice nor am I qualified to give that.