1, RGP glasses sufficient oxygen supply can protect the health of the eye cornea. Suitable for: (1) People with high refractive error. (2) Astigmatism up to 2.50D, and can not be equipped with toric lenses. (3) Long wearers and those who wear them for long periods of time. (4) Those who are not suitable for soft contact lenses due to stubborn lens deposition or inflammation. Sun Kang, Ophthalmology Department, Foshan Chancheng District Central Hospital 2. In special cases, the good corrective vision performance of RGP contact lenses can be corrected: (1) Patients with a slight cone cornea. (2) aphakic eyes (cataract surgery can not be implanted after the IOL) (3) mild dry eye patients 3, RGP hard contact lenses adaptation period is slightly longer than soft lenses, generally about one to two weeks. Unsuitable people for RGP 1.People who work in acidic or alkaline and dusty environment 2, excessively timid, neurotic and psychotic patients. 3.Poor living habits. Those who are restricted in the occupational environment of slovenly households. 4.Patients with ocular allergy, chronic blepharitis and acute ocular surface inflammation. 5.Pterygium and other causes of uneven corneal surface.