In 1884, Viennese ophthalmologist Karl Koller discovered that a mild solution of cocaine applied to the eye would deaden the nerves' sensitivity to pain.
Notes on verification
Well-documented in medical history sources, encyclopedias, and peer-reviewed literature; consistent details across multiple independent references.
Sources
- Cocaine, the Victorian wonder drug | Wellcome Collection (wellcomecollection.org)
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140169/ (ncbi.nlm.nih.gov)
- https://www.aao.org/history-of-ophthalmology/karl-koller (aao.org)