The patient arrives in the emergency department (ED) or clinic complaining of severe, intense, burning eye pain, usually bilateral, beginning 6 to 12 hours after a brief exposure without eye protection to a high-intensity ultraviolet (UV) light source, such as a sunlamp or welder’s arc. The eye examination shows conjunctival injection and tearing; fluorescein staining may be normal or may show diffuse superficial uptake (discerned as a punctate keratopathy under slit-lamp examination). The patient may also have first-degree burns on their skin.