occur after traumatic injury or chronic compression of the oculomotor nerve. Sometimes aberrant regeneration involves the medial rectus fibers and pupillary contraction occurs during attempted adduction. This synkinetic pupil movement can resemble light–near dissociation.

Other Pupillary Disorders

Benign Episodic Pupillary Mydriasis

Also known as springing pupil, benign episodic pupillary mydriasis typically occurs in young, healthy individuals who frequently have a history of headache. Episodic mydriasis may last from minutes to hours and may be accompanied by mild blurring of vision, periocular discomfort, and headache. Each episode is self-limiting, and the condition has not been associated with any systemic or neurologic disease.

Jacobson DM. Benign episodic unilateral mydriasis: clinical characteristics. Ophthalmology. 1995;102(11):1623–1627.