This study investigated the diagnostic accuracy of three traditional Chinese medicine (TCM) eye-based diagnostic systems (Wu Lun, Ba Kuo, Ba Gua) and equine clinical disease. An ocular exam was performed on 103 horses which included photo documentation of both eyes. Findings from the exam, using each of the different TCM diagnostic systems, were compared to known medical history of a subject horse and the clinical presentation during the enrollment visit. An overall diagnosis accuracy score of each TCM eye assessment system was evaluated against the chance level, and the differences among the three systems were compared. Based on a subject horse’s past medical history, all three eye diagnostic systems had overall diagnostic scores significantly greater than 0 (null hypothesis), demonstrating better than chance diagnostic accuracy: p=5.8×10-13, 1.9×10-13, 9.4×10-11 for Ba Gua, Ba Kuo and Wu Lun respectively. Statistically significant findings for diagnostic accuracy were also obtained based on a subject’s clinical presentation at study enrollment: p=8.2×10-15, 3.0×10-14, 5.3×10-13 for Ba Kuo, Ba Gua, Wu Lun respectively; all with smaller p-values (more significant) than the results for past medical history. Comparison of diagnostic score outcomes did not reveal significant differences among the three eye-based diagnostic systems (p=1.000 and 0.243, based on past medical history and clinical presentation, respectively). This study provides early evidence-based findings that the three TCM ocular assessments could prove helpful in diagnosing clinical disease and Zang-fu organ imbalance in the horse and should be considered as a useful adjunct to equine clinical TCVM examinations.