Study of the incidence and characteristics of motility alterations following various operations for retinal detachment. Diplopia and asthenopia following retinal surgery are rare, despite relatively frequent muscular imbalance, because of: (a) suppresion (which war frequently found even in orthophorics with good postoperative vision in both eyes); (b) compensation owing to fusional power, and (c) probable role of the sensory factor for the compensation of the subjective experience of cyclotropia. However, asthenopia and diplopia may occur and may be hard to deal with. It is felt that these disorders could be avoided in many cases since they are frequently the result of technical errors.