Optograms and criminology: science, news reporting, and fanciful novels

A persistent nineteenth-century urban legend was the notion that photograph-like images of the last-seen object or person would be preserved in the eyes of the dead. This popular notion followed technological developments (the daguerreotype and ophthalmoscope) that antedated by decades a basic understanding of retinal physiology. From 1876 to 1877, Boll described photochemical bleaching of the retina and produced a crude retinal image that remained briefly visible after death in an experimental animal. From 1877 to 1881, Kühne elaborated the processes involved in photochemical transduction, and created more complex retinal images, or "optograms," that were visible after the death of experimental animals under special laboratory circumstances. In 1880, Kühne reported the first human "optogram" when he examined the eyes following the state execution of a convicted murderer. Although the work of these physiologists increased public interest in "optography" as a potential tool in forensic investigations, Kühne and his student, Ayres, concluded after an extensive series of investigations that optography would never be useful for this purpose. Nevertheless, because of the prior tantalizing results, optography became a frequent consideration in speculative news reports of sensational unsolved murders, and as a plot device in works of fiction, some quite fantastical. Fictional portrayals included works by Rudyard Kipling and Jules Verne. Despite denouncement of optography for forensic investigations by Kühne, and by numerous physicians, the general public and mass media continued to press for examination of the retinae of murder victims well into the twentieth century, particularly in high-profile unsolved cases.