OBJECTIVES: Ophthalmologists have to face various acute or chronic painful diseases. They miss specific tools assessing ocular pain. Our objective was to develop and validate a tool to quickly and precisely describe patient's complaint, measure pain intensity and elicit possible causes. METHODS: Different types of quantification and description of pain identified from the literature were proposed to 20 patients suffering from acute or chronic painful ophthalmic diseases. A questionnaire was developed, validated by an Advisory Committee (AC) and tested with 8 other patients. The pilot questionnaire was produced and validated by the AC. A cross-sectional, observational study was carried out to validate the questionnaire for a use in clinical practice and to provide a typology of painful ocular pathologies. The questionnaire was completed by 536 consecutive patients presenting with pain complaint in 43 centres. The clinicians completed a medical form and assessed the questionnaire's usefulness and feasibility in clinical practice. RESULTS: The test questionnaire was developed taking into account the preference given by patients to visual analogous or graduated scales to quantify pain, and to pictograms to describe pain. This test version was considered valid and easy to use, except for the emotional descriptors of pain. The pilot questionnaire contained five sections : “General Health”, “Eyes and eyesight”, “Pain”, “Pain relief”, “Pictograms and sensorial descriptors”. A description of pain characteristics was provided for the most frequent painful diseases, including traumatisms (183), ocular surface diseases (71), cornea pathologies (58). A total of 27 ophthalmologists evaluated the questionnaire and 78% of them considered it helpful for patient management. CONCLUSION: The ODEON® questionnaire is a unique, promising tool designed for use in clinical practice to allow patients with ocular pain to comprehensively quantify and describe their pain in a standardised format. Further work is needed to establish specific recommendations