Assuming the home test counts for your driving licence
Licence vision certificates must come from centres accredited by the licensing authority, which file results electronically — a standard home visit is not that. People pay AED 150–400 at home, then discover they still need the approved-centre test. Use the home visit as preparation, and ask about accreditation before booking if the licence is your whole reason.
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.