Snellen chart
Snellen chart: history of visual acuity testing from Hooke to ETDRS, with key milestones, optotype design, and contributions from Snellen, Donders, Sloan
Tag Heinrich Küchler
Heinrich Küchler
Heinrich Küchler (1811–1873): German ophthalmologist who pioneered early eye charts, advanced corneal surgery, and reformed medical and military health services