<p>Disclosed is a method for adequately producing a high-performance optical material (such as a lens) composed of a polyurethane resin, which optical material is clear and colorless, while having no strain. In this method, the optical material is produced without causing cord or white turbidity by polymerizing a polymerizable composition characterized by containing 10-300 ppm of moisture and composed of a polythiol compound and a polyiso(thio)cyanate compound.</p>
