Positive photosensitive composition for forming lenses containing 1,2-naphthoquinone diazide sulfonate photosensitizer, alkali-soluble resin and thermosetting agent and process for producing the composition

A positive photosensitive composition for forming lenses, which comprises in admixture a polymer in an amount effective to maintain transparency when said lenses are heated again after being molded, a photosensitive agent in a photosensitizing effective amount, a thermosetting agent in an amount effective to impart heat resistance and solvent resistance to said lenses, and an amount of a solvent sufficient to at least dissolve the polymer, photosensitive agent and thermosetting agent, wherein said polymer is an alkali-soluble resin having an aromatic ring component and a carboxylic acid component partially modified by esterification or amidification, a vinyl phenol polymer or a hydrogenated vinyl phenol polymer having hydroxyl groups modified by alkylation, acylation or sulfonylation, or a novolak polymer or a hydrogenated novolak polymer having hydroxyl groups modified by alkylation, acylation or sulfonylation, said photosensitive agent is a 1,2-naphthoquinone diazide sulfonate and said thermosetting agent is a thermosetting agent capable of imparting heat resistance and solvent resistance at the time of forming lenses by heat treatment.