In the late 1800s, there was a popular scientific belief that the last image seen by a dying person or animal was “recorded” on their retina.
An early camera, c1905.
Therefore, if one could figure out the process, one could “develop” the retina like a photograph to show that image. It sounds fairly wild to the modern ear, but is this concept fact or fiction? Surprisingly, the answer is it’s both. Let’s take a closer look.
An image developed from a dead retina is called an “optogram” and the process is called “optography.” To a 19th-century ear, this concept didn’t seem as far-fetched as it does today. Not only was our understanding of modern medicine still growing by leaps and bounds, but photography was brand new technology. Also, people were aware of the linguistic links between the human eye and a camera — for example, there is a lens in both the eye and a camera, and a camera aperture moves very similarly to a human iris. So, in a time where new discoveries were being made every day, it wasn’t a wild idea to suggest that eyes might be able to permanently capture images.
“Willy” Kühne
As it turns out, some of this theory is true! In 1876, a physiologist named Franz Christian Boll discovered rhodopsin, a visual pigment in the retina that blanches in light but regains its purple hue in the dark. Boll called this “visual purple.” Next, another physiologist named Wilhelm Friedrich Kühne created a procedure that fixed the bleached rhodopsin in the retinas of dead rabbits by washing them in a solution of alum.
According to Kühne, the pattern in the image below is the image of a barred window that the rabbit was looking at immediately before it died. This was enough proof that he soon tried to apply this method to deceased human retinas, but without success. In this circumstance, optography for rabbits specifically seems to be fact.
Can you see the window?
However, applications of Kühne’s experiments quickly jumped into the realm of fiction. Based off a fundamental misunderstanding of Kühne’s process, law enforcement in the United Kingdom and eventually the U.S. tried to apply optography to criminal investigations. However, they were not taking freshly dead retinas and developing them in a solution of alum. This forensic optography consisted of photographing a murder victim’s eyes and trying to divine the killer’s face from whatever patterns the photograph showed.
Even though this procedure is not scientifically sound, that didn’t stop forensic optograms from being used in famous criminal cases and from appearing on real trial records. In 1888, British police inspector Walter Dew wrote about a forensic optogram taken of murder victim Mary Jane Kelly, hoping that the face of her killer, the infamous Jack the Ripper, could be identified in the picture.
A contemporary cartoon portraying Jack the Ripper, 1888.
Then over 25 years later in 1914, a U.S. grand jury admitted a forensic optogram as evidence in the case of the murder of 20-year-old Theresa Hollander, although the boyfriend suspected of her murder was found not guilty.
Although forensic optography is scientific fiction, it quickly also became a fixture in fiction literature and media. Forensic optograms have appeared in Jules Verne novels, performed by “Dracula” actor Béla Lugosi, and even served as a plot point on the television show “Doctor Who.” So, while we can conclusively say that developing pictures from retinas is both fact and fiction, it would appear that optography’s impact has been far stronger and longer-lasting in the world of popular culture than in the world of science.
This 1936 film features forensic optography.