Uncertainty analysis of eye axial length measuring instrument

The axial length measuring instrument is an ophthalmic examination device used to measure data such as axial length of the eye. It is widely used in clinical examinations of ophthalmology, such as refractive surgery examination, diagnosis of myopia in adolescents, cataract surgery, and other fields. The axial length measuring instrument based on optical principles has advantages such as non-invasive and non-contact inspection. Therefore, it has been widely applied. However, there is a serious lag in the metrological calibration work. In this article, the main focus is on the study of an eye axial length measuring instrument based on optical principles. Mainly about the calibration method of axial length. This article is based on the industry standard YY/T 1484-2016 "Ophthalmic Instruments - Axial Length Measuring Instrument". By designing cylindrical axial length standards of different specifications, they are used to simulate short, medium, and long axial lengths. Calibration and uncertainty analysis of NIDEK Corporation's AL Scan axial length measuring instrument. The purpose is to establish a complete traceability system for the measurement values of axial length measuring instruments and support the safety of clinical treatment.