A history of the femtosecond laser in the United States and Europe

Johannes Kepler, a world-renowned astronomer and mathematician, published Dioptrice in 1611.¹ This classical literature laid the groundwork for optical instruments such as the telescope and introduced the diopter, a unit of measurement central to our work in cataract and refractive surgery. Today, we strive to achieve 0 diopters (ie, emmetropia) and spectacle independence for our patients, a goal made increasingly attainable through advances in technology, including the femtosecond laser.