An object is to find the minimum activity expression site of fibronectin, clarify the actions of this minimum unit in relation to ophthalmological fields, and provide a ophthalmological composition having this minimum unit as an effective component. This invention provides an ophthalmological composition, in particular, a corneal disorder treatment agent containing the peptide, PHSRN (Pro-His-Ser-Arg-Asn), or Ac-Pro-His-Ser-Arg-Asn-NH2, which is a derivative thereof, or a salt thereof that is allowable as a medical drug as an effective component. The preferred dosage form is an ophthalmic formulation.
