The actual illuminated spectacle examination is carried out in a dark room or a heavily darkened room. The internal illumination of the spectacles breaks the patient's optical contact with the environment (eliminating the fixation that prevents nystagmus). However, brightly illuminated eyes are particularly easy to observe under magnifying spectacles. In many cases, abnormal nystagmus processes can be detected by looking straight ahead which cannot be detected reliably or at all without glasses, even when looking sideways. The power supply for the nystagmus spectacles is provided by either the DEHAG battery box type 504 or the plug-in power supply type 506 (both not supplied). The DEHAG battery box is powered by three 1'5 volt C size LR14/AM-2 batteries (baby batteries). The adjustable battery holder handle allows you to adjust the brightness individually by turning the switch slightly. The pluggable power supply is connected via a standard household socket (100-240V/AC, 50/60Hz). The Frenzel 501 Nystagmus Spectacles operate with two 4-volt lamps, which can be purchased from medical supply stores.
