The sight test is a loss-leader and everyone in optics knows it, but very little optical marketing is built as though it were true. The NHS sight test fee is set nationally and sits well below what the chair time actually costs a practice, and the eligibility list is broad enough that a large share of your book arrives funded at that rate: everyone under 16, 16 to 18 in full-time education, everyone aged 60 and over, patients with diabetes or glaucoma, people over 40 with a close relative diagnosed with glaucoma, those registered sight impaired, complex lens patients and anyone on the qualifying income-related benefits. The margin is in what happens after the test — frames, lens options, coatings, contact lens plans. Which means the only marketing number worth optimising is the cost per dispense and its average value, and the number nearly every practice actually reports is appointments booked. Those two can move in opposite directions, and frequently do: a campaign advertising a free test fills the diary with people who already qualified for a free test and had no intention of buying glasses.
The competitive picture is unusually lopsided. Specsavers, Vision Express and Boots Opticians run national brand advertising with budgets no independent can approach, and the Specsavers joint-venture model means each store also markets locally with that brand behind it. Trying to win a generic sight test search in your town against that is an expensive way to lose. Where independents genuinely have room is the clinical and dispensing ground the chains cover thinly: myopia management for children, OCT imaging, dry eye clinics, complex or specialist contact lenses including scleral and orthokeratology, low vision, sports and occupational lenses, and independent eyewear brands the chains do not stock. Those searches are lower in volume and far higher in intent, the person searching has usually already been told they need something specific, and in a lot of towns there is no local page competing for them at all.
Then there is the rhythm of the market. Most people are recalled every two years, so at any given moment the addressable audience is a small slice of your list plus whoever has just moved into the area or broken their glasses. You are not selling to a town of forty thousand people; you are selling to the few hundred whose recall is due this month, and to a handful of walk-in problems. That has two consequences. Catchment is small and proximity-weighted — people choose an optician near home, work or the school run, so the map pack decides more than the website does. And the cheapest demand you have is the list you already own: a recall programme by email and SMS, with the practice's own reminders arriving before the chain's do, reliably returns more than the equivalent spend on acquisition. Seasonality is mild but real, with children's eyewear clustering around the start of term and prescription sunglasses lifting in spring.