The invention relates to a medicament, the active principle of which is a leucine and, for example, a N-ACETYL-DL-LEUCINE. It can be applied to the prevention and/or treatment of eye diseases or disorders and especially of hereditary dystrophies of the retina, glaucomatous neuropathy, glaucoma, macular degeneration, myopia, presbyopia, hypermetropia, astigmatism, all the ophtalmologic diseases or disorders inducing a decrease of visual function and/or age-related physiological vision decline.
