The clinical features of superior oblique paresis vary widely depending on the type. Common features of a unilateral superior oblique palsy include an ipsilateral hypertropia that increases on contralateral gaze and a positive head tilt test with the hypertropia increasing on head tilt to the side of the hypertropia. Almost all unilateral superior oblique palsies are congenital associated with ipsilateral inferior oblique overaction and relatively little superior oblique underaction. The head tilt test can help to differentiate primary inferior oblique overaction from inferior oblique overaction secondary to superior oblique paresis. A positive head tilt test indicates a superior oblique paresis, and a negative head tilt test suggests primary inferior oblique overaction.