I’m going to show you the last thing a rabbit ever saw. It, in turn, will show you why Victorian-era people believed that a murder victim’s eyes contained a “photograph” of the person who murdered them.
In the Victorian era, people began to work with cameras instead of paint brushes. It was common knowledge that special chemicals could react to an image and then be fixed, creating a perfect picture. Anyone, with the right chemicals, could do it. In 1857 it occurred to one Wilhelm Kühne that a similar chemical process might happen in the eye. He obsessively studied rhodopsin, the pigment found in photo receptors. He discovered that it bleaches in the light, and that the eye needs some time, after continuous exposure, to replace it. He was then ready to conduct the creepiest experiment in the world.
First he grabbed an albino rabbit. He secured it in one place, strapping its head down so it could only look one direction—out a barred window. He covered the rabbit’s head with a cloth. He kept the rabbit’s head covered for several minutes, and whipped off the cloth. After letting the rabbit stare at the window for several more minutes, he decapitated it, sliced its eye in half, and went to work with fixing chemicals. He got the image displayed to the left. Yep, that’s the barred window, fixed on the retina of a dead rabbit. None of us will ever sleep again.
When he published his results, Kühne called his process optography, and it became a sensation. The public was fascinated. This fascination gave rise to a new idea. Surely, if the last thing we saw is literally fixed on the retina, then society would no longer need a living witness to give evidence in a murder case. A murder victim would surely have stared at his or her killer, so the eyes of murder victims should contain images of their attackers.
It’s no wonder the idea struck a chord. There’s something compelling about the image of the guilty fixed forever in the eyes of the innocent. (It recalls old medieval stories about how sometimes doctors found the name of some guilty person branded on the heart of the person they wronged.) Optography as evidence made its way into mystery novels, and for a while, whenever a particularly sensational murder case shook society, people would write to the police frantically advising them that, if they would only check the eyes of the victim, they would solve the case.