Ask! How long has that person been doing fittings? In general, someone with more than 5 years' optical experience in independent stores or labs will usually have the knowledge to do the job correctly. Ask if they are an ABO Certified Optician. All of our staff are certified.
The best customer is a well-informed one, and of course your vision is irreplaceable. Here are answers to frequently asked questions.
Progressive lenses work! They are the most sophisticated method of correcting presbyopia available, and work very well for the vast majority of people, but as in anything else, Caveat Emptor. There are over forty different progressive lens brands, some of them good, and some not so good. In general the best progressive lenses, fitted by a skilled optician, and understood by the patient will work and work well.
In general, TRUE premium lenses are seldom discounted, heavily advertised, or available at bargain prices. Nor are they usually available at superstores. The manufacturers of Premium lenses are concerned with their reputation too; and only offer them into the hands of skilled opticians. Don't expect to find the very best at national retailers or chain stores.
Lens design/material accommodation is a very individual experience; different people, react differently. While one person has a lot of difficulty getting used to a new way of seeing things, another person has absolutely no trouble at all.