Professional adjustments can make a slightly wrong size work better. My optician taught me what can and cannot be adjusted.
Lens width, bridge width, and temple length are fixed. If these measurements are wrong, adjustments won't help. I need the right base size first.
I bought 52-18-140 frames that felt slightly off. My optician adjusted the temple curve and nose pads. Now they fit perfectly. The base size was right - adjustments just fine-tuned it.
Perfect fit through professional adjustments, but only because I started with the right base measurements.