Cone dark adaptation: the influence of halothane anesthesia.

Cone dark adaptation (da) (measured with an electroretinogram [ERG] method) is found to be severely retarded when the subject (human and macaque monkey) is under halothane anesthesia. The degree of retardation depends both on the halothane level and on the bleach history. The effect of bleach history shows a great similarity with psychophysical findings concerning foveal da. Interpretation of halothane effects, therefore, is possible in terms of an existing model on cone pigment kinetics.