But when there is a disruption and the muscles do not work together, some form of strabismus, including exotropia, may occur. Other causes may involve the nerves that transmit information from the brain to the muscles, or the part of the brain that directs eye movements.
de facto segregation-segregation (especially in schools) that happens in fact although not required by law. separatism, segregation-a social system that provides separate facilities for minority groups.
in fact; in reality: Although his title was prime minister, he was de facto president of the country. Although the school was said to be open to all qualified students, it still practiced de facto segregation. 2. actually existing, especially when without lawful authority (distinguished from de jure). noun.