Ortho-k is believed to safe when appropriately fitted and managed properly. Unlike surgical procedures like radial keratotomy(RK), photorefractive keratectomy (PRK), laser assisted in-situ keratomileusis (LASIK) and laser assisted subepithelial keratectomy (LASEK), the corneal tissue (the front surface of the eye) is not incised or vaporised by a laser or scalpel. As with all contact lenses, proper lens care and handling must be performed to maintain eye health. The state-of-the-art, high permeability GP materials now available provide adequate amounts of oxygen to the tissues of the eye.