It is pointed out that the mental and emotional state of the patient is overlooked in the treatment of errors of refraction; the author states that the eye rarely produces other than ocular symptoms unless the patient is emotionally unstable, also that some form of psychotherapy is more likely to relieve him than the use of glasses. The headache for which glasses are so frequently worn is out of proportion to the strain produced by the error of refraction. This and other symptoms are definitely related to emotional causes and are relieved by treatment directed to these factors. The result of questioning one hundred consecutive cases elicited the fact that the error of refraction was not such an important cause of the symptoms as the mental complexes. A description of two cases of glaucoma follows in which the symptoms are directly traced to the emotional factor. Unequal pupils and watering of the eyes have also been proved to have had an emotional foundation. The author has noticed an existing relationship between squint and left-handedness; this has also been referred to by Dr. W. H. Rivers. The