Both subjective and objective optometry can accurately measure the diopter number and astigmatism of the patient. These two methods need to have rich experience in optometry, and it takes a long time to master the technology of image inspection, and the computer optometry technology is easier to learn and master. Computer optometry for a large number of group examinations or outpatient optometry, especially for outpatient diagnostic optometry and check the refractive changes before and after the treatment of eye diseases, without dilation and can quickly measure the degree of refractive error. The optometry results are all automatically printed, do not need to be converted, generally a few seconds to a few minutes to determine a patient, and can quickly determine the degree of refractive error, for lens correction to provide more accurate diopter number and distance between pupils.
There are different opinions on the accuracy of diopter measured by computer optometer. The accuracy of the computer optometer is affected by many factors, such as the poor coordination of the patient's head and eyes, moving around, the eye fixation on the target in the optometer is not concentrated enough, resulting in insufficient relaxation and adjustment, which will inevitably affect the accuracy of the diopter test results, and even the degree of repeated examination is greatly different. For children and patients with refractive interstitial opacity, the error of computer optometer test is large, and even can not check the diopter number. There are errors in the stability and repeatability of the computer optometer, so it is inappropriate to use the diopter number measured by the computer as the sole basis for optometry. The degree measured by the computer optometry is often higher than the degree of the optometry, so the computer optometry can not replace the optometry and lens correction technology, only to provide a useful reference for manual optometry.