AIM: To study the effects of Sodium Hyaluronate (HA) and Bion Tears on corneal thickness in adult myopic patients.METHODS: A total of 38 cases (76 eyes) were involved in this study. Three consecutive corneal measurements (the thinnest point of the cornea,THN) were evaluated before and half an hour after the instillation of one drop of HA in one eye and Bion Tears in the other at random with the Orbscan Corneal Topography System II (Orbscan,Inc,Salt Lake City,UT,USA,Version 3.00E).RESULTS: There were no significant between-group differences in baseline variable (t=0.264). Thirty minutes after the instillation of HA and Bion tears,THN were significantly increased by 5.57±7.00μm (t=4.906,P<0.01) and 7.89±7.64μm (t=6.369,P<0.01) respectively. However,there were no between-group differences in THN changes(t=1.381,P>0.05).Increase in the corneal thickness were found in 32 eyes (84%) and 33 eyes (87%) for the HA and Bion tears group,respectively.CONCLUSION: Artificial tears including HA and Bion Tears can significantly increase the corneal thickness in a short period of time. Corneal thickness can be used as one of the objective indices for evaluating the quality and therapeutic role of artificial tears.