Caloric nystagmus: ENG in comparison with observation by Frenzel's glasses.

After caloric stimulation with water at 30 degrees C for 30 sec an electronystagmogram (ENG) was registered. Simultaneously with the ENG the test person's nystagmus was observed by Frenzel's glasses. If the evaluation is limited to the frequency of the nystagmus and if it is possible to neglect the velocity of the slow phase, the simple observation through Frenzel's glasses and its plotting on a time chart recorder is no less effective than an ENG for measuring the difference between the right and left labyrinth.