The morning of November 16, 1880, Wilhelm Friedrich Kühne (1837–1900), a professor of physiology at the University of Heidelberg, dissected the head of an executed murderer in his dark room within minutes of the man’s death. Kühne worked around the contracting muscles in the left eye socket to remove the eye and develop an image from the retina of the last thing this man saw.1
According to Douglas Lanska in “Optograms and Criminology: Science, News Reporting, and Fanciful Novels,” (from Literature, Neurology, and Neuroscience: Historical and Literary Connections) Kühne equated “vision to a repetitive photographic process” and he considered the eyes to be “whole photographic workshop.”1 He believed it was possible to develop images, like photographs, from the eyes of the dead. Kühne called the image fixed on the corpse’s retina an optogram, and the process of developing this image optography. If his experiment on the murderer’s head was successful, then optopgrahy had the potential of revolutionizing the investigation of violent crime.
Cross-section of the human eye. Image from Wikipedia.
Kühne’s research was inspired by the work of physiologist Franz Christian Boll. In 1876, Boll discovered a pigment in the rods of the human retina that bleaches in the light and is restored in the dark. Kühne took this observation a step further by demonstrating that retinal pigment, which he called “visual purple” (also known as rhodopsin), remains after death unless the retinas are exposed to light. 1 Also, if light hits the retinas post-mortem then a photochemical reaction takes place that bleaches this tissue. To develop optograms, he needed to find a way to fix the rhodopsin in the retina.2
Kühne first conducted optography experiments on frogs and rabbits. Lanska describes the macabre process that Kühne used to get his animal optograms. He secured the heads of rabbits and frogs so they remained motionless and were forced to stare at windows or gas flames. After the animals had gazed at these objects for hours, Kühne cut off their heads, removed the eyes, and dissected the halves containing the retinas. To fix the rhodopsin, the light-sensitive tissue was hardened in an alum solution and then immersed in sulfuric acid in a dark room.1
Kuhne rabbit optogram (1878). Image from Wikipedia and the College of Optometrists.
Kühne’s best-defined retinal images came from his rabbit experiments in 1878. He secured rabbits so that they were forced to stare at windows in the daylight. The resulting optograms were so distinct that individual windowpanes could be seen on the right side of the retina.
But optography was problematic for forensic investigations. Kühne conducted hundreds of experiments, and even in the most ideal circumstances most optograms were hazy and quickly faded. He also discovered that the eyes had to be removed very quickly after death otherwise the eye started to decompose and images couldn’t be retrieved.
On November 16, 1880, Kühne got his first and only chance to get a human optogram with the execution of Erhard Gustav Reif. Reif was convicted of drowning his two youngest children and was sentenced to death by guillotine. Because the eyes had to be removed soon after death, Kühne had to remove Reif’s eyes within minutes of the guillotine blade falling,
Drawing of the human optogram from Reif’s eye. From: Wikipedia and the College of Optometrists.
Supposedly Kühne was able to develop an optogram from Reif’s retina but only the drawing of the image exists. The optogram loosely resembles a guillotine blade, but it wasn’t possible for Reif to have seen the blade before his decapitation because he was blindfolded before the blade fell. Some, like Derek Ogbourne, who created the Museum of Optography, believe the shape may represent the steps he climbed to get to the guillotine. 2
Many 19th-century forensic scientists and doctors felt optograms were of little use to murder investigations because the images were hazy and faded quickly. One such physician was W.C. Ayres, an American who worked with Kühne on his numerous optography experiments. Ayres’ position on forensic optography was summarized in an 1881 issue of Microscopical News and Northern Microscopist, which reported that he believed it was “utterly idle to look for the picture of a man’s face, or of the surroundings, on the retina of a person who has met with a sudden death, even amid the most favourable circumstances.”3
Despite the objections of doctors and detectives early on, optograms were used occasionally in forensic contexts in the 20th century. They were famously admitted as evidence in the murder trial of Fritz Heinrich Angerstein (1891–1925), a German man accused of killing his wife and seven other people on December 2, 1924. During the post-mortem examinations, the coroner in this case reportedly had the retinas of two of the victims photographed because he saw an image of the murderer holding a hatchet. Optography was rumored to also have been used in the Jack the Ripper case.
Although forensic optography has been thoroughly debunked, fiction writers can’t seem to get enough of the idea, and it has been used numerous times as a plot device: Jules Verne included it in his 1902 novel Les Freres Kip; it was used in two episodes of Doctor Who (one in 1975, the other in 2013); and an optogram was developed from the optic nerve of murder victim in a 2008 episode of Fringe.
Resources cited
- Lanska, D. (2013) Optograms and Criminology: Science, News Reporting, and Fanciful Novels. In Stiles, A; Finger, S.; and Boller, F (Eds.), In Literature, Neurology, and Neuroscience: Historical and Literary Connections. Oxford, UK: Elsevier.
- Ogbourne, D. (n.d.). Optography and optograms. Retrieved from: http://www.college-optometrists.org/en/college/museyeum/online_exhibitions/eye/optography.cfm
- Permanent Eye Pictures. (n.d.). In Davis, G.E. (Eds). Microscopical News and Northern Microscopist, Volume 1. London, UK: Tubbs, Brook, & Chrystal.