Visual diagnosis: 2-month-old girl with left eye swelling, profuse tearing.

Nasolacrimal duct (NLD) obstruction is the most common cause of persistent tearing in a child younger than 1 year. Other possible causes include congenital eyelid abnormalities, chemical irritation, trauma, occult foreign body, congenital or early-onset glaucoma, and conjunctivitis. • In addition to NLD obstruction signs, dacryocystoceles also present with swelling over the nasolacrimal sac.