A member asked if the omission of a vertex distance on a prescription was a problem when they knew the spectacles were being dispensed online. My first thought was, “It can’t be” – but closer attention threw up some difficult issues.
All prescriptions over +/-5.00D need a vertex distance; this includes those you know are being taken to someone else to be dispensed. If the patient is over 16 and neither SI nor SSI, anyone may dispense that prescription, even if it is a high power and requires a vertex distance. An unregistered person may make such alterations to the power dispensed when the vertex distance of the spectacles differs from that on the prescription.
Now you can immediately see the problem: the supplier of the online spectacles cannot measure the vertex distance of the chosen frame and thus cannot make any correcting calculation. Of course, we understand the potential problems of such spectacles but our patients do not; it might be helpful to explain such difficulties, politely, to the patient but most, I suspect, don’t care. “But they’re cheap!” is all the comment you get.
In this instance, my advice to our member was that the optometrist or ophthalmic medical practitioner must give the prescription in an accurate, legal form at the completion of the eye examination; this must include a vertex distance if the power exceeds five dioptres. This is also true of any duplicate prescriptions. If a patient chooses to have that prescription dispensed online where the vertex distance cannot be established, that in itself is not illegal. Whether the online (registered or not) seller is committing an offence has not yet been tested in law.