Background <p>Sterile corneal infiltration is an inflammatory condition typically associated with contact lens wear, staphylococcal hypersensitivity, or corneal procedures. Chemical injuries usually present with diffuse epithelial defects or stromal haze, whereas the development of a discrete sterile corneal infiltrate following chemical injury appears to be uncommon. We describe an unusual case of unilateral sterile peripheral corneal infiltration following accidental chemical injury caused by contact lenses soaked in a makeup remover.</p> Case presentation <p>A 35-year-old woman presented with severe ocular pain and decreased vision after briefly wearing soft contact lenses that had been mistakenly soaked overnight in a makeup remover solution. Slit-lamp examination revealed near-complete epithelial defects in both eyes. In the left eye, a ring-shaped peripheral stromal infiltrate spanning approximately 270° was observed, with a distinct lucid interval and intact overlying epithelium. Microbiological investigations, including bacterial and fungal corneal cultures and viral polymerase chain reaction testing, were negative for infectious pathogens. The patient was diagnosed with bilateral chemical injury and unilateral sterile corneal infiltration. The patient was managed with antimicrobial coverage, cautious anti-inflammatory treatment, autologous serum, and intensive lubrication, followed by gradual epithelial healing and complete resolution of the infiltrate within two months.</p> Conclusions <p>Chemical toxicity from contaminated contact lenses may trigger a localized sterile immune-mediated corneal infiltrate that can mimic infectious keratitis. Careful slit-lamp examination and recognition of clinical features such as a lucid interval and intact epithelium are important for distinguishing sterile from infectious infiltrates and for guiding appropriate treatment.</p>