Glasses adjusted over 7 times and still not fitting

Hi

I bought new glasses last November. They were fine for maybe a month and this year I have been back to the opticians at least once a month needing adjustments as they are too loose and are sliding down my nose. Initially they were also crooked but this seems to have been sorted. I have worn glasses for 32 years and I have never needed to go back more than once for adjustments after getting new glasses.

This time after the adjustments they feel fine and then after 2 to 3 weeks they loosen again. I wear them 100% of the time so when I am not wearing them they are on a bedside locker or in a case. I am very careful with them. I have taken to bringing my last pair of glasses with me on holidays as I am afraid they will be knocked off my face. I took them off for an exercise class this week as I was fed up of pushing them up constantly. My prescription is around -8 and -3.5 so I felt uncomfortable without them.

When I go in for adjustments I just pop in with no appointment so it is often different people adjusting them. I rang today asking for appointment and explained all this. I have an appt with someone this weekend and I said in future i want to use the same person so they can see the movement in the glasses after a few weeks. Every time I go in I tell them I have been in x number of times now. Once one of the opticians before said it could be because of my prescription as it is strong. However, it is only marginally stronger than my last pair of glasses and I always take the opticians advice on appropriate frames that will work for me when buying new glasses.

My issue is I don't know if the issue is how the opticians have been fitting them or is it the glasses. Is it normal for glasses to move/adjust so much? What do I need to say at my appt? They know all of the above. I just want my glasses to fit and not have to go back every 3 weeks or so for adjustments.