Pain present: Corneal abnormality (e.g., abrasion, erosion, foreign body or rust ring, edema), anterior uveitis, eyelash or eyelid disorder (e.g., trichiasis, entropion), conjunctival foreign body, dacryocystitis, dacryoadenitis, canaliculitis, trauma.
Minimal/no pain: Dry eye syndrome, blepharitis, nasolacrimal duct obstruction, punctal occlusion, lacrimal sac mass, ectropion, conjunctivitis (especially allergic and toxic), crocodile tears (congenital or seventh cranial nerve palsy), emotional state.
Children: Nasolacrimal duct obstruction, congenital glaucoma, corneal or conjunctival foreign body, other irritative disorder.