Consensus on Diagnostic Criteria, Clinical Symptoms, and Risk Factors for Visual Fatigue: A Modified Delphi Study

INTRODUCTION: Visual fatigue is becoming increasingly prevalent globally, while universally accepted definitions and standardized diagnostic criteria remain lacking. This study aims to develop consensus-based recommendations on the definition, diagnostic criteria, core symptoms, risk factors, and assessment of visual fatigue, using a modified Delphi process to support standardized clinical and epidemiologic practice. METHODS: A modified Delphi process was conducted with an international panel of experts in optometry, ophthalmology, and related disciplines. Two rounds of questionnaires were used to generate candidate definitions, diagnostic criteria, symptoms, risk factors, assessment methods and management principles. A subsequent hybrid meeting was held to discuss unresolved items and consolidate the final recommendations. RESULTS: Of 20 experts invited, 14 participated in the panel (response rate 70%); 13 (92.8%) completed the round-2 questionnaire and 12 (85.7%) took part in the hybrid discussion. The final consensus comprised three major recommendations with 13 constituent items. Recommendation 1 defines visual fatigue as a functional disease characterized by a core symptom set and functional impact and emphasizes identification of common associated conditions. Recommendation 2 specifies a structured assessment pathway including essential clinical examinations for confirming visual fatigue and ruling out comorbidities, and the use of questionnaires and objective assessments where available. Recommendation 3 focuses on prioritizing high-risk populations, targeting modifiable risk factors, and principles for management and outcomes to track in future work. CONCLUSIONS: This consensus provides a foundational framework for addressing the growing global burden of visual fatigue by defining it as a distinct functional disease and providing a structured diagnostic framework and a stepwise management approach. It offers a foundation for the global standard of care for visual fatigue.