High accuracy in testing for spontaneous or provocation nystagmus is indispensable in present-day vestibular diagnostics. An examination for nystagmus using Frenzel spectacles is performed in a darkroom or a thoroughly darkened room. Frenzel spectacles have an internal illumination unit that cuts off the test person’s visual contact with the surroundings, eliminating any nystagmus-inhibiting fixation. Then the examiner can closely observe how the patient’s brightly illuminated eyes move under the spectacles’ magnifying lenses during forward gaze and diagnose any nystagmus.
42902 | Nystagmus spectacles acc. to Frenzel, battery version, type 703 |
42903 | Nystagmus spectacles acc. to Frenzel, 4 V alternating voltage, type 501 |