Book excerpt: From monocles to pince-nez and goggle-eyes, a cultural and technological history of glasses in fact and fiction. This book examines those who wore glasses through history, art, and literature, from the green emerald through which Emperor Nero watched gladiator fights to Benjamin Franklin’s homemade bifocals, and from Marilyn Monroe’s cat-eye glasses to the famed four-eyes of Emma Bovary and Harry Potter. Spectacles are objects that seem commonplace, but In the Blink of an Eye shows that because they fundamentally changed people’s lives, glasses were the wellspring of a quiet social, cultural, and economic revolution. Indeed, one can argue that modernity itself began with the paradigm shift that transformed poor eyesight from a severely limiting disease—treated with pomades and tinctures—into a minor impairment that can be remedied with mechanisms constructed from lenses and wire.