1, treatment principle: OK lens myopia correction is a special contact lens to change the curvature (curvature) of the cornea of myopic patients, reduce myopic refractive error, so as to improve visual acuity method. The special contact lenses are called OK lenses or keratoplasty lenses, which are made of high-tech materials with good oxygen permeability and are specially designed by computer according to the examination data of each patient. This method does not require surgery, is safe to use, easy to operate, and quick results. 2, treatment effect: The United States has four universities to complete research about OK lens, they are the University of Houston College of Optometry (5 years); California University San Diego School of Medicine (7 years); California University Berkeley College of Optometry (3 years) and Oregon Pacific University College of Optometry (5 years). The results of all studies show that OK lenses are safe, reliable and effective in correcting myopia. The use of high-tech materials, innovation in lens design and computerization of production and processing are the keys to the great success and wide acceptance of the OK lens technology by doctors and patients. Patients with mild or moderate myopia who use OK lenses have seen a significant reduction in refractive error and can achieve surprising improvements in their vision in a very short time. 3.Treatment procedure: OK lens correction includes three stages: examination, correction and maintenance. First, patients are examined to determine if they are suitable for correction; then, patients are scheduled to wear custom-made OK lenses at night for correction. The best correction is usually achieved within 1-2 weeks; finally, when the doctor confirms that the vision has been restored to its best, the patient will continue to wear the lenses for 4-12 months. In order to maintain the correction effect for a long time, different patients can intermittently wear them as appropriate. 4, the advantages of OK lens vision correction: short-term vision can be improved. Myopia refractive error reduction effect is good, more can no longer need to wear glasses or contact lenses. Easy to operate, easy to use. No risk, other eye functions are not affected. Inhibits the development of progressive myopia in adolescents. Can meet the requirements of certain special occupations (such as athletes, divers, pilots, actors, police, military, etc.) for distance vision. 5, OK lens treatment indications: age 7 ~ 50 years old, healthy, no eye disease; can cooperate with contact lens wear; K value in 38D ~ 47D can be corrected, with 40 ~ 45D good effect; myopia in less than 600 degrees, astigmatism less than 100 degrees.