In 1950, two researchers noticed something that didn’t quite add up. Hector Chevigny, a writer who had lost his sight in adulthood, and psychologist Sydell Braverman were studying the psychological lives of blind people when they stumbled upon an intriguing pattern: schizophrenia, a serious mental illness affecting people across virtually every known society, appeared to be entirely absent in people who had been blind from birth.
The observation sat largely ignored for decades, held back by limited understanding of the disease and a lack of patient data. Then, in the early 2000s, large national health databases allowed researchers to follow entire populations from birth into adulthood, and the pattern held up.
