The owl story is repeated in nearly every account of iridology's origin and is presented as its founding moment, but the accounts trace to later iridological literature rather than to anything Peczely wrote. It has the shape of a foundation legend.
What would resolve this A statement by Peczely himself, or a contemporary account, describing the observation. Absent that, the earliest attestation of the story would at least date the legend.
Resolution Sourcing note, 2026-07-25 (W4). Cited to Ernst 2024, whose abstract hedges the owl story with the word allegedly; the chapter body is paywalled. Searched for a primary attestation and found none. Peczely's own 1881 brochure, Entdeckungen auf dem Gebiete der Natur- und Heilkunde, is not digitised anywhere reachable, so it could not be checked for the owl. The claim circulating on Wikipedia that Peczely's nephew August called the story apocryphal at the First International Iridological Congress rests on a single self-published web page and should not be repeated until a real source for it is found. Berggren, Iridology: a critical review, Acta Ophthalmologica volume 63, 1985, pages 1 to 8, is paywalled at Wiley and is the next thing to read.
OpenHistory of medicine, and Hungarian-language archival sources.Edzard Ernst, Ignaz von Peczely, Inventor of Iridology