Engineers have developed a noninvasive approach to permanently correct vision that shows great promise in preclinical models. The method uses a femtosecond oscillator for selective and localized alteration of the biochemical and biomechanical properties of corneal tissue. The technique, which changes the tissue's macroscopic geometry, is non-surgical and has fewer side effects and limitations than those seen in refractive surgeries. The study could lead to treatment for myopia, hyperopia, astigmatism, and irregular astigmatism.