In 1898, Dutch ophthalmologist Dr. Leendert Jan Lans investigated the effects of corneal incisions to correct refractive errors. His findings predate the conclusions of Fyodorov of Russia by almost 75 years and are similar to what is now understood about radial keratotomy.
So fundamental and comprehensive was his research that it soon became the standard of refractive surgery. He practiced and promoted the principles of corneal flattening that could be achieved by incisions made on the anterior surface of the cornea. By varying the number, direction, and shape of the incisions, Dr. Lans could manipulate the effects and tailor the visual correction.