Ophthalmometer

*Ophthalmometer* is an optical device designed to determine a person’s vision by measuring indicators of binocular perception of visual functions. Ophthalmometry is based on the use of special optotypes and tests, and also provides the ability to monitor their changes as a result of the progression of age-related farsightedness, presbyopia, myopia or astigmatism. For proper operation of the ophthalmometer, it is necessary to ensure the correct location of the light source. In ophthalmometric measurements, optotypes with a wavelength of 480 - 530 nm are used, which corresponds to the radiation of an incandescent lamp. The wavelength of light stimuli must match the efficiency of the photoreceptors. This is an important condition for light adaptation and measurement of light sensitivity at different periods of the visual cycle. Incorrect position of the lamp can lead to noticeable disturbances during measurements. It has a particularly bad effect when working on devices with recorders (graphs). It is not allowed to use other light sources as a lamp when performing ophthalmometry, since they do not meet the conditions of stimulation, effective photobiological stimulation and correction of visual impairment.