Rigid Gas Permeable (RGP) lenses are hard contact lenses that allow oxygen to pass through the lens material into the eye, promoting better corneal health. These lenses are smaller and firmer than soft contact lenses, maintaining their shape on the eye and providing superior visual acuity. RGP lenses are particularly beneficial for patients with corneal irregularities or complex refractive errors that cannot be corrected by soft lenses. They are commonly used for conditions like keratoconus, astigmatism, and post-surgical eyes, where stability and clarity are critical.