Medical optometry means that under the guidance of ophthalmology and optometry theory, the refractive state of both eyes is detected by various subjective and objective methods, mainly by means of photographic techniques, and then a comprehensive judgment is made based on the examination results of eye position, adjustment, binocular monocularity and collective function of the examined person, combined with his or her age, occupation, eye habits and other factors, and a scientific prescription is given to enable the wearer to perform his or her binocular monocular function normally, so as to achieve clear, comfortable and long-lasting visual effects. A complete medical optometry includes the following procedures and principles: 1. ophthalmic history inquiry and general eye examination; 2. routine optometry (computerized optometry, shadowing, film insertion, etc.); 3. examination of astigmatism axially, cis-regular astigmatism is appropriately undercorrected, retro-regular or oblique astigmatism is adequately corrected; 4. examination of eye position, internal oblique is undercorrected for myopia and adequately corrected for hyperopia; external oblique is vice versa; 5. adjustment power determination, strong adjustment power is appropriately undercorrected for myopia and adequately corrected for hyperopia; 5. 6.Check the dominant eye (dominant eye), so that before and after wearing the glasses are consistent; 7.Check the visual function of both eyes, so that the adjustment of both eyes wearing corrective lenses is in balance; 8.Accurately measure the pupillary distance, in order to maintain the center of the visual axis of both eyes and the optical center of the glasses; 9.Try on the glasses and prescribe.