A portable ERG system with an automatic driven LED Ganzfeld stimulation contact lens.

A portable ERG system with a Ganzfeld stimulation and adaptation light source is described. The stimulus flash energy can be selected from a range of 3.9 log units and the adapting background can be 0,10 or 100 lux at the cornea. The whole system has the dimensions of a standard ECG recorder, can operate independently of the main voltage and can be used in electrically unshielded rooms. It has a programmed measuring cycle that controls the paper transport, the changeover of the registration channel from one eye to the other, the stimulus presentation and the registration of a standard calibration pulse (100 microV/100 ms).