Retinal image of murderer

It was popularly believed in the late 19th and early 20th c., that an image of the last thing that a dead person saw was imprinted on his or her retina. An optogram from a murder victim's eye would therefore reveal the murderer. The belief is referred to by James Joyce (1882-1941) in Ulysses:

They looked. Murderer’s ground. It passed darkly. Shuttered, tenantless, unweeded garden. Whole place gone to hell. Wrongfully condemned. Murder. The murderer’s image in the eye of the murdered. They love reading about it.

I didn't find an optogram--real or imagined--to accompany this post, but I did find this monotype of Joyce by Aubrey Schwartz, this great site about anatomical tattoos and street art, and the definitive article about the retinal image idea:

Looking for the “photo in a dead person’s eye” soon became an accepted police investigative procedure and an established touchstone of much turn-of-the-century SF and detective fiction. In later 20th century literature and film, a modern variant of the optogrammic photo emerged: the dead brain itself was now “read” using high-tech scanners to record the deceased’s final vision (or thoughts) before death occurred. The goal of this article is to examine this pseudoscientific literary motif, its origins and evolution, and to show how science fact can sometimes become science fiction and take on a life of its own in the popular imagination.

The idea figured in the Jack the Ripper investigation, and there exist several photographs of his mutilated victims, but do not click on this link if you would rather not see them.