The clinical, histopathological, ultrastructural and microanalytic features of a case of iatrogenic ocular argyrosis are reported. The case, in a 63-year-old woman with long-standing herpetic keratitis, was unusual in that it occurred after apparently only one treatment with eyedrops consisting of a 1% solution of "mild silver protein" (Argyrol). Another unusual feature was that the silver deposited in the cornea was mainly conjugated to sulfur; selenium, which commonly demonstrates a high affinity for silver in tissues, was detectable in only trace amounts.