Freak Pictures, Fly Fishers, and Optical Illusions: Historical Antecedents of the Science of Fish Vision

In the early twentieth century, when little was known about the underwater realm, the question of subaquatic vision garnered much interest. Based on human laws of optics in water, observers of the time claimed to show how fish see, and the impact of illusions on fish vision. Addressing fly-fishers in particular, they raised the question of whether fish see “freak pictures” and “monsters.” The present study examines five scientific visualizations published in Scientific American in 1913 to determine whether optical illusions remain relevant for fish scientists today and whether conceptions of visual intelligence in fish have changed since 1913.