Final answer:
The drug chlorpromazine, used as an antipsychotic medication, can lead to endothelial/Descemet's pigmentation of the cornea, especially at high doses and with prolonged use.
Step-by-step explanation:
The drug that can cause endothelial/Descemet's pigmentation of the cornea, specifically, is chlorpromazine. Chlorpromazine is a typical antipsychotic medication used to treat various psychiatric disorders. It can lead to pigmentary changes in the cornea and the lens upon prolonged exposure, especially at high doses. The pigmentation is due to deposition of the drug or its metabolites and often occurs in a stellate or star-shaped pattern in the posterior corneal stroma and Descemet's membrane. While mostly cosmetic, these changes can rarely affect vision and are typically more pronounced in individuals with lighter colored irises and in those exposed to sunlight without protective eyewear.