Uses of melanin and its derivatives, analogs, and precursors for the treatment and prevention of ocular diseases, disorders, and conditions, are described. Melanin, or a derivative, analog, or precursor thereof, such as synthetic melanin or natural melanin, is applied to the eye by topical application or injection. Examples of ocular diseases, disorders, and conditions that can be treated or prevented by the methods described herein include hyperemia, leukoplakia, corneal angiogenesis, and corneal keratoconus.