All professional attendances after the first, being those attendances regarded as a single service, in a single course of attention involving the prescription and fitting of contact lenses, for patients who, because of physical deformity, are unable to wear spectacles, being a course of attention for which the first attendance is a service to which item 10905, 10907, 10910, 10911, 10913, 10914, 10915 or 10916 appliesApplicable once in a period of 36 months