| Description | These are rigid gas permeable contact lenses used for corneal refractive therapy, a process that temporarily corrects nearsightedness (myopia). The patient wears the lenses overnight while sleeping and removes them upon wakening. During the day, | These are rigid gas permeable contact lenses used for corneal refractive therapy, a process that temporarily corrects nearsightedness (myopia). The patient wears the lenses overnight while sleeping and removes them upon wakening. During the day, |