According to Dr. Blessing, the lighting of the nystagmus glasses is indirect, so no light reflection can occur, which leads to unwanted, nystagmus-inhibiting gaze fixation in the patient. Since the shielding of the lighted bulbs prevents direct illumination of the eye, no PURKINJE vein image is created, the movement of which can trigger a random "illuminated glasses nystagmus", so false positive nystagmus findings can be ruled out. The actual lighted glasses test is done in a dark room or heavily darkened room. The internal illumination of the glasses interrupts the optical contact of the patient with his environment (elimination of anti-nystagmus fixation). At the same time, strongly illuminated eyes can be observed particularly well under the magnifying glass. In many cases, abnormal nystagmus processes can be observed when looking straight ahead, which cannot or cannot be reliably detected even when looking to the side without glasses. The nystagmus glasses are powered by either the DEHAG type 504 battery housing or the type 506 plug-in power supply (both not included). The DEHAG battery holder is powered by three 1.5 volt CLR14/AM-2 sized batteries (baby cells). Through the adjustable battery handle, you can adjust the brightness individually by turning the switch slightly. The plug-in power supply is connected via a standard household outlet (100-240V/AC, 50/60Hz).
