During dioptometry, a lensmeter is used to determine complete analysis of glass lenses. The current eyeglasses of the patient are inserted into the device and their optic strength is determined. Analysis of monofocal (spheric and cylinder-shaped), bifocal and progressive eyeglass lenses is possible. By using the obtained data, the ophthalmologist, assesses the suitability of the current lenses and, if required, prescribes new.