I assume it was a more extensive glaucoma test than the air-puff or the torsion bar thing they often do routinely at the optometrist's office?
A lot more involved. Opthalmology is involved, not eyeglass vendors.
It was a very complicated, two-hour test at a glaucoma specialist clinic, designed to tell if some anomaly in one eye is a natural condition or early glaucoma that could possibly be prevented. But of course, after two hours and nearly $500, they still couldn't tell. More tests!!