Accepting a verbal prescription or a 'we'll make your glasses' promise
Without a complete written prescription including pupillary distance, you are captive to the tester's own glasses pricing. The written document is what makes the market work for you — any optical shop can fill it. No paper, no payment.
Booking separate visits for one household
The call-out cost is baked into every solo booking, so a family that books three separate visits pays the travel premium three times. Almost every vendor discounts additional people in the same visit, typically AED 80–200 each. Bundle the household, especially outside Dubai and Sharjah where travel is a bigger slice of the quote.
Skipping the licence check because the price was good
An unlicensed test is the most expensive kind: a wrong prescription means headaches and wasted glasses, and an unqualified tester can miss signs that needed a doctor. Verifying a DHA, DoH or MOHAP licence takes two minutes. Booking through a platform that verifies vendors first handles the initial filter, but asking directly costs nothing.