Purpose Unifying terminology for the description of ocular surface disease (OSD) is vital for determining treatment responses and ensuring robust clinical trial outcomes. To date, there are no agreed parameters describing ‘activity’ and ‘damage’ phases of disease. Methods A working group of international experts in OSD, oculoplastics, and uveitis from a range of backgrounds (university, teaching, district general and private hospitals) participated in a modified Delphi consensus-building exercise (October 31, 2011 to March 20, 2015). Two steering group meetings took place in which factors based upon published literature were discussed and supplemented with anonymous web-based questionnaires to refine clinical indices according to ‘activity’ (reversible changes resulting directly from the inflammatory process) and/or ‘damage’ (persistent, >6 months duration) changes resulting from previously active disease that are cumulative and irreversible). Results The recommended set of clinical parameters for the assessment of OSD encompasses 68 clinical indices and 22 ancillary grading tools (in parenthesis) subdivided by anatomical domain as follows: 4(4) tear-film, eyelid 21(3), 17(3) conjunctiva, 15(10) cornea and 11(2) Anterior Chamber/Sclera. Of these; 17(2) were considered as measures of clinical activity, 27(3) as damage, 1(8) as measures of both activity and damage. Twenty-three clinical descriptors and 9 tools did not reach the threshold for inclusion into the main standard set. These were defined as ‘second tier’ parameters for use in special clinical settings. Conclusion These core parameters provide the first description of ‘activity’ and ‘damage’ relevant to OSD and provide a platform for the future development of scoring scales for each parameter.