Effects of eyelash extensions on the ocular surface: a systematic review of clinical outcomes and adverse events

Topic To synthesise evidence on ocular surface outcomes, symptoms and adverse events associated with semi-permanent eyelash extensions. Clinical relevance Eyelash extensions are applied beside the ocular surface; their clinical effects and associated complications warrant assessment. Methods PubMed, Ovid, CINAHL and Scopus were searched to 3 September 2026 without date or language restrictions for primary human studies reporting extension-specific ocular or periocular outcomes. Two reviewers independently screened studies, extracted data and appraised studies using adapted Newcastle-Ottawa and Joanna Briggs Institute tools. Findings were synthesised narratively owing to heterogeneity. The review followed PRISMA 2020 and a prospectively registered protocol (PROSPERO CRD420261383757). Results Nineteen studies were included: two prospective studies, five cross-sectional studies, four case series and eight case reports. In one prospective study, corneal staining peaked at one hour and tear-film stability was lowest at one week after application. A matched comparator study found between-group differences in tear break-up time and clinical signs. One removal study showed improvement in symptomatic users. Four self-report studies included 845 users; symptom prevalence ranged from 26.8% to 97.5%, reflecting different samples and methods. Reported adverse events included keratoconjunctivitis, contact dermatitis, bacterial keratitis and eyelid leukoderma. Conclusion Eyelash extensions are associated with ocular surface disturbance and diverse adverse events, involving exposures beyond the adhesive. Small uncontrolled studies, self-reported surveys and case-level evidence limit certainty and prevent population-risk estimation. The findings support clinical enquiry about extension use in patients with unexplained ocular surface or perioperative symptoms.