4.3 Inch LCD Screen Digital Pupil Distance Meter Pupilometer Digital Pd Meter Digital Pd Meter PD-400 Uses Digital PD Meter is a precision optical instrument used to measure distance between pupils in the process of optometry for spectacles. Characteristics The instrument is composed of six parts: measurement system, optical system, electronic conversion system, computer software, visual liquid crystal display system, and rechargeable lithium battery power supply system，the following characteristics： 1) Using the HD camera to dynamically observe the subject, both eyes can be adjusted at the same time to improve the measurement speed. 2) Using a visual measurement interface in HD，The optometrist visually observes the screen and adjusts it through the LCD screen，Minimize the visual error from monocular observations. 3) Change the traditional measurement patterns，The optometrist is no longer in close contact with the subject，Effectively prevent the infectious risk of infectious diseases or viruses and ensure the health of the patient. 4) The mechanical hairspring is used to aim the reflecting point of human eyes, which has the characteristics of direct sampling point, high alignment accuracy and fast measurement speed. 5) Using high-precision linear sensor, advanced intelligent electronic system, digital display of measurement results, intuitive, easy to read, accurate characteristics. 6) With the latest measurement algorithm, the measurement results of the distance of view needed by the user.