ABSTRACT
There are many systems for classifying nystagmus which is present at birth or noted in early infancy. The use of the term ‘congenital nystagmus’ to describe nystagmus seen in this period is disputed, and the terms ‘early onset’ and ‘infantile’ nystagmus may be encountered. Some authors include manifest latent and latent nystagmus as forms of congenital nystagmus (see separate topic). Congenital-infantile nystagmus (CN) has an approximate incidence of 1 in 6550 live births, and a consistent pattern of clinical features. It may be classified as:
(a) Idiopathic (no identifiable underlying ocular pathology). This is sometimes termed congenital motor nystagmus, or congenital benign idiopathic nystagmus.
