Medical apparatus and instruments for monitoring heart rate; medical apparatus and instruments for monitoring heart beat; medical apparatus and instruments for monitoring biometric information; medical apparatus for preventing or reversing heart failure; medical instrument for cardiovascular diagnostics; heart rate monitors; medical diagnostic apparatus for testing atrial fibrillation; medical diagnostic apparatus for testing arrhythmia; medical diagnostic apparatus for testing heart failure; medical diagnostic apparatus, analytical apparatus for medical purposes and blood pressure measuring apparatus; heart rate monitoring apparatus; apparatus and instruments for the remote measurement of patient information, namely, temperature, heart rate, pulse rate, glucose level, body weight assessment, blood pressure and transcutaneous oxygen level for medical purposes; medical testing device used to monitor brain waves and heart rate to adjust and regulate heart rate variability for the purpose of relaxation and peak performance, namely, disposable electrodes; medical analysis equipment for the biochemical composition of the body being flow cytometers and flow-based analyzers providing particle analysis, detection, and counting for medical use; pulse meters; biometric information monitor, namely, sensors for medical diagnosis to be worn by humans to gather and analyze biometric data; none of the above in the field of optometry and ophthalmics, in particular, augmented, virtual and mixed reality glasses and headsets