THE PRESENCE of distinct defects in the electroretinogram (ERG) in the varying forms of night blindness has been well documented in recent reports. The most conspicuous changes have been recorded from frank cases of primary pigmentary degeneration of the retina. In these cases the tracings are usually extinguished or greatly reduced in amplitude.* A recent article in the Japanese literature4 describes similar but less marked changes in Oguchi's disease. Bornschein and Vukovich5 have observed subnormal recordings with avitaminosis A, and definite changes have also been seen in cases of congenital night blindness without fundus change.† This latter form of nyctalopia appears to us to be of more interest than other forms. The existence of clear-cut alterations is of pertinent significance when clinically evaluating alleged night blindness—especially in the military service. In the past such patients have been frequently looked upon as psychiatric problems, if not actually designated as