This case report presents the clinical scenario of a 50-year-old man who developed swelling and itching around both eyes after applying tropicamide eye drops for an ophthalmic examination. The swelling appeared suddenly, progressed over time, and was accompanied by redness, watery discharge, and conjunctival congestion. A dermoscopic examination revealed congestion and erythema in the affected area. Visual acuity was compromised in the left eye. Prompt identification of the eyedrops as plain tropicamide with chlorbutol as a preservative enabled timely treatment with intravenous hydrocortisone and topical steroids, resulting in symptom improvement within two days. Allergic reactions to mydriatic agents such as tropicamide are infrequent but should be considered in patients with acute ocular symptoms postapplication. This case underscores the importance of recognising and managing allergic reactions to ophthalmic medications for optimal patient care.