In a retrospective study of 397 children operated in the course of 10 years (1985-1995) on account of essential infantile esotropia the authors evaluate the effect of early surgery implemented before the age of two years on the quality of binocular vision as compared with a later operation. The group of children was divided into three sub-groups. Group A comprised 75 children with the operation during the first six months of life (mean 3.8 months), sub-group B 194 children with the operation at the age of 6-24 months and in group C 128 children operated at the age of 2-6 years (mean 3.56 years). In group A binocular vision was recorded in 80 % children (15 % superposition, 60 % fusion, 5% stereopsy). In groups B binocular vision was recorded in 76 % children (18 % superposition, 50 % fusion, 8 % stereopsy). In group C simple binocular vision in the form of superposition was present in 24% and fusion only in 21% children. The results of binocular vision after surgery of essential infantile esotropia are in favour of early surgery, preferably by the age of 6 months, not later than at the age of 2 years. An essential part of comprehensive treatment is active and positive pleoptic and orthoptic care incl. supplementary surgical correction of residual horizontal or vertical deviations. Early surgery of an adquate extent with a safeguarded parallel position of the eyes implies in the long run more frequent achievement of a higher quality of binocular vision incl. stereopsy.

        Key words: infantile esotropia, surgery, binocular vision