The present invention provides a food (particularly a supplement, a health supplement, a food for specified health uses, a food having a nutrient function, or a food having function claims) and a preparation for external application (particularly a medicine (a medicine for medical uses, an OTC), a quasi drug, a cosmetic, and a skin care product), each of which contains an NAD-related metabolite or a pharmaceutically acceptable salt or prodrug thereof. The present invention also provides a pharmaceutical composition for preventing or treating an ophthalmic disease selected from the group consisting of presbyopia, glaucoma, diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, chorioretinal atrophy associated with high myopia, corneal endothelial dystrophy , bullous keratopathy, cataract, retinal artery/vein occlusion, Fuchs' s corneal dystrophy, bullous keratopathy, optic neuropathy and Leber' s disease.