| Conjunctival neoplastic lesion | More vascular and irregular in consistency and shape than a pterygium; typically unilateral; usually arises from the interpalpebral fissure |
| Conjunctivitis | Inflammation of the bulbar and/or palpebral conjunctiva; red eye with mucoid or serous discharge; burning, sandy, gritty sensation; no associated visual impairment; etiology may be viral, bacterial, or allergic |
| Episcleritis | Inflammation of the episcleral tissue between the conjunctiva and sclera; abrupt onset of redness, irritation, and eye watering |
| Pinguecula | Conjunctival degeneration presenting as a yellowish, slightly raised conjunctival lesion arising at the limbal conjunctiva |
| Pterygium | Triangular wedge of soft, nearly flat fibrovascular conjunctival tissue that starts medially on the nasal conjunctiva and extends laterally onto the cornea; it is white and amorphous or thick; may have redness or irritation |