Pain

Ocular:
- Typically mild to moderate: Dry eye syndrome, blepharitis, infectious conjunctivitis, episcleritis, inflamed pinguecula or pterygium, foreign body (corneal or conjunctival), superficial punctate keratopathy, superior limbic keratoconjunctivitis, ocular medication toxicity, contact lens–related problem, postoperative, ocular ischemic syndrome, eye strain from uncorrected refractive error (asthenopia).
- Typically moderate to severe: Corneal disorder (e.g., abrasion, erosion, infiltrate/ulcer, chemical injury, ultraviolet burn), trauma, anterior uveitis, scleritis, endophthalmitis, acute angle-closure glaucoma.
Periorbital: Trauma, hordeolum, preseptal cellulitis, dacryocystitis, dermatitis (e.g., contact, chemical, varicella zoster, or herpes simplex), referred pain (e.g., dental, sinus), giant cell arteritis, trigeminal neuralgia.
Orbital: Trauma, sinusitis, orbital cellulitis, idiopathic orbital inflammatory syndrome, orbital tumor or mass, optic neuritis, acute dacryoadenitis, migraine or cluster headache, microvascular cranial nerve palsy, postherpetic neuralgia.
Asthenopia: Uncorrected refractive error, phoria or tropia, convergence insufficiency, accommodative spasm, pharmacologic (miotics).