Acute red eye in contact lens users: Clinical pearls for frontline clinicians

Contact lens wear is common, and patients with related acute red eye often present first in non-ophthalmology settings, including emergency departments, urgent care centers, family medicine practices, and primary care clinics. In these settings, access to slit-lamp examination may be limited, and even when available, accurate interpretation depends on clinician experience. Acute red eye in contact lens users may reflect noninfectious inflammatory disease, but it can also signal early microbial keratitis, which may initially present with subtle or nonspecific findings. Delayed or missed recognition can lead to progressive corneal damage and visual loss. Despite increasing contact lens use and the risk of vision-threatening complications, practical, evidence-based guidance tailored to frontline non-ophthalmologist clinicians remains limited. When bacterial keratitis is suspected and timely ophthalmology evaluation cannot be confirmed, frequent topical fluoroquinolone therapy may be needed because commonly used topical antibiotics may not provide adequate corneal coverage. This review aims to provide clear, practical guidance to improve triage, support timely referral, and prevent avoidable corneal morbidity, particularly in underserved settings where access barriers may worsen outcomes and follow-up.