Example of an opinion of an Advocate General, delivered in connection with Case C-271/92, 'Laboratoire de prothèses oculaires', on the subject of the free movement of goods. Advocate General Tesauro considers whether the requirement of a professional qualification for the sale of optical products constitutes 'a measure having equivalent effect to a quantitative restriction' within the meaning of Article 30 (new Article 28) and, if so, whether this restriction is justified by the imperative requirements of the protection of health under the terms of Article 36 (new Article 30). The Advocate General, carrying out his examination in the light of the case law of the Court, places the case in its context and deduces the main issues. The task of the Advocate General to provide clarification is clear: as he classifies the judgments of the Court into three groups, corresponding to three different kinds of solutions, he systematises the Court's approach in respect of the free movement of goods, thus rendering it easier to comprehend.