Sudden-onset squint.

Differentiating a sudden-onset concomitant squint from a paralytic squint in an ill child can be difficult, but the distinction is important in view of the neurological implications of the latter. Furthermore, the two types may co-exist, and four such cases are described. The causes of sudden-onset squint are discussed. Methods of examination are described which may help to distinguish a paretic squint, with its neurological implications, from a concomitant deviation with no such systemic associations.