Non-corneal electroretinogram. Parameters in normal children.

In the investigation of suspected visual disorders electroretinography (ERG) is of con- siderable clinical value. The ERG is usually recorded from a contact-lens type of electrode placed over the cornea. Although this is possible in co-operative adults using only local anaesthesia, the placement of a contact lens electrode in a young or retarded patient is usually not tolerated without a general anaesthetic. Because of the obvious disadvantages of requiring general anaesthesia for such a test procedure, a method was developed in this department at the beginning of I968 to record the ERG from an electrode placed between the eyes on the bridge of the nose. The ERG recorded from such an electrode is of small