Introduction to Corneal Disorders By Melvin I Roat, MD, FACS, Sidney Kimmel Medical College at Thomas Jefferson University Reviewed / Revised Aug 2022 | Modified Sep 2022 View Patient Education Symptoms that suggest corneal involvement (eg, rather than simple conjunctivitis) include unilateral involvement, pain (foreign body sensation and ache—not just a gritty sensation), particularly with exposure to light (photophobia), and decreased visual acuity.