To provide a ultraviolet-curable composition which has excellent light resistance even when exposed to light of a fluorescent lamp, and forms an optical disk with a suitable photo-curing property, and to provide the optical disk.

The optical disk having excellent light resistance when exposed to light of a fluorescent lamp is formed from a composition which is a ultraviolet-curable composition to be used for a light transmitting layer of an optical disk, and which contains a (meth)acrylate oligomer, a (meth)acrylate monomer, a polymerization initiator, and an ultraviolet absorber, the ultraviolet absorber being expressed by formula (1), and the polymerization initiator having an absorption region at 400 nm or higher, without reducing productivity when a curing property is reduced. In formula (1), R1and R2independently represents a hydrogen atom, a 1-12C alkyl group, a 1-6C alkoxyl group, or a 1-12C alkyl ester, and X represents a hydrogen atom, a halogen atom, a 1-12C alkyl group, a 1-6C alkoxyl group, a cyano group, or a nitro group.

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