Monocular strabismus (Human Phenotype Ontology entry HP_0010877) can be described as follows. A type of strabismus in which the fixating eye is always the same one, while the other eye is constantly deviated. Monocular strabismus is to be distinguished from alternating strabismus, in which either of the eyes 'squints' at different times. Also known as: Unilateral strabismus.