In this review of the electrophysiology of extraocular muscle, Dr. Breinin gives particular attention to the scientific literature on ocular electromyography. This literature is quite recent but the bibliography is growing at a rapid rate. Fundamental advances in the knowledge of extraocular muscle function in health and disease have accrued in the investigations being conducted in many laboratories and the author provides a comprehensive summary of information on the theoretical and practical applications of electromyography to the extraocular muscles and the contributions of the technique to the general problem of strabismus. Controversial observations are discussed at length, experimental studies are reported, and new bio-electronic computing techniques are described. Recent studies from the author's laboratory on the physiologic and pharmacologic properties of extraocular muscle are also described. The study is issued under the sponsorship of the American Ophthalmological Society.