Christiaan Huygens' Telescope Lenses Tell Us He Was Nearsighted

A world-famous 17th-century astronomer credited with discovering Saturn's moon Titan may have needed glasses, according to a recent paper in the Royal Society Journal of the History of Science. In an era when telescope technology was less than a century old, and evolving rapidly through trial-and-error iterations, Christiaan Huygens was known for producing lenses of …