Bilateral herpes simplex keratitis was induced in rabbit corneas. The infected corneas were treated with either neutral red dye followed by exposure to fluorescent light or with idoxuridine ointment. Dye-light treatment produced a faster cure rate than idoxuridine.
Tara CS, Stanley JA, Kucera LS, Hollis S. Photodynamic Inactivation of Herpes Simplex Keratitis. Arch Ophthalmol. 1974;92(1):51-53. doi:10.1001/archopht.1974.01010010055013