Four university level research studies have been completed on Orthokeratology. These studies include: the University of Houston College of Optometry (5 years); University of California at San Diego Medical School (7 years); University of California at Berkeley School of Optometry (3 years); and Pacific University School of Optometry (5 years). All studies found the procedure to be safe, without harmful side effects, and effective. These studies stressed that proper care and continued monitoring of patients under treatment is required. Only experienced practitioners in the field of contact lens therapy should utilize the procedure.