The truth about images stored in the eyes of… the dead

For a long time, scientists have wondered whether the eyes can retain images of our last glance before we die?

And it wasn't until the invention of the camera that this fascinating subject was widely studied.

Failed Experiments

Scientist Wilhelm Kühne saw the picture in the rabbit's eye as it died.

In 1876, German physiologist Franz Christian Boll discovered rhodopsin - a photosensitive protein in the rod cells of the retina , which acts like nitrate on a camera lens, bleaching when exposed to light.

Unfortunately, Boll's life ended prematurely at the age of 30 due to tuberculosis, preventing him from pursuing further research. However, these findings were enough to convince the scientific community that changes in rhodopsin play an important role in the functioning of vision.

After Boll's death, one of his admirers, the German physiologist Wilhelm Kühne, took up the discovery with 'burning enthusiasm' . Kühne began experimenting on a variety of animals, removing eyes very soon after death and using various chemicals to fix images on the retina.

The following story by biochemist George Wald, who won the Nobel Prize in 1967 for his work on visual pigments, describes one of Kühne's most successful experiments with a rabbit:

An albino rabbit is tied up, facing a barred window. From this position, the rabbit can see only a gray, cloudy sky. Its head is covered with a cloth for a few minutes to allow its eyes to adapt to the dark, that is, to allow rhodopsin to accumulate in the rod cells of the eye.

The animal was then exposed to light for three minutes, then decapitated and the eyes removed, the posterior half of the eyeball containing the retina was placed in an alum solution for fixation. The next day, Kühne produced a photograph of the window with a clear pattern of iron bars imprinted on the retina of the rabbit's eye.

Kühne was eager to practice this technique on human subjects, and in 1880, an opportunity arose. On November 16, death row inmate Erhard Gustav Reif was sent to the guillotine for murder in the nearby town of Bruchsal.

Ten minutes after the execution, his eyes were removed and sent to Kühne's laboratory at the University of Heidelberg. The optograms (photographs, or images from the eyes of a dead person) that Kühne made of Reif's eyes do not survive, but a sketch of what was seen on Reif's retina appeared in Kühne's 1881 paper 'Observations on the Anatomy and Physiology of the Retina' .

It is unlike anything a condemned man would have seen at the moment of his death. However, some have suggested that the outlines resemble the blades of a guillotine, although the victim could not have seen them because he was blindfolded. Others have suggested that they could be steps leading to the gallows. Kühne has offered no explanation for the images.

Physiologist Franz Christian Boll discovered the photosensitive substance rhodopsin, which helps the eye function like a camera.

Prospects for forensics?

Although Kühne failed to obtain clear optical images from human eyes, the idea that the deceased retained their final images in their eyes continued to have a strong impact on the imagination of many people at the time.

When it was suggested that retinal scans from murder victims could help identify murderers, the French Society of Forensic Medicine asked Dr. Maxime Vernois to conduct a study to test the feasibility of using retinal scans as evidence in murder trials. Vernois killed 17 animals and dissected their eyes, but found nothing.

Despite Kühne and Vernois's unsuccessful experiments, other researchers persisted in photographing the eyes of murder victims in the hope that the images might help solve criminal cases. Detectives around the world have suggested using the technique on murder victims.

Rumors of the dead retaining their last images in their eyes were so widespread that some murderers sought to destroy their victims' eyeballs after they had killed them.

By the early 20th century, investigators had given up hope that optics could be developed into a useful forensic technique. However, in 1975, the police in Heidelberg, Germany, asked scientist Evangelos Alexandridis of the University of Heidelberg to use modern scientific techniques, up-to-date knowledge, and advanced equipment to re-examine Kühne's experiments and findings.

Following Kühne's lead, Alexandridis attempted to produce some high-contrast images from rabbit eyes. However, he concluded, optics had no potential as a forensic tool.

And this was the last case of serious scientific optical research aimed at producing images from the eyes of the dead. Despite this, the concept has long lived in science fiction and detective fiction.

The famous science fiction writer, Jules Verne, also maintained the belief that optics had potential in crime investigation through his 1902 novel 'Les Frères Kip '. Over the next hundred years, the idea appeared frequently in literature and media. The 1936 film 'The Invisible Ray' featured a scene where Dr. Felix Benet, played by Bela Lugosi, uses an ultraviolet camera to photograph the eyes of his deceased victims.