To report a case of toxic keratopathy secondary to the self-application of seawater eye drops. A 60-year-old male who presented with unexplained unilateral decrease in vision and corneal thinning. Best-corrected visual acuity was 20/400 OD, slit-lamp examination indicated diffuse corneal edema with central thinning, intact sensation, and no vascularization. Laboratory analysis of the eye drops in conjunction with clinical symptoms and findings was consistent with toxic keratopathy. Toxic keratopathy can masquerade as the other forms of keratopathy, and a thorough history taking and laboratory analysis may help elucidate the diagnosis and avoid significant visual morbidity.