Myopia can be tested through subjective and objective optometry. Myopia refers to a kind of refractive error phenomenon caused by the long eye axis or abnormal lens adjustment; generally, it is necessary to determine the degree of myopia through optometry; optometry is divided into subjective optometry and objective optometry; subjective optometry refers to a kind of optometry that requires the participation of the patient, and the common ones are comprehensive optometry and insertion of film optometry, etc. Objective optometry does not require the participation of the patient, but only follows the requirements of the examination; if the patient is not required to participate, it is enough to follow the computerized optometry and photographic optometry. Objective optometry does not require the participation of the patient, only need to follow the requirements of the examination can be, common computerized optometry, photoplethysmography, etc.; if the patient has the need to determine myopia, it is recommended to go to the regular optometric institutions for examination, in the doctor or optometrist under the guidance of the combination of subjective optometry and objective optometry to determine the true degree of myopia.