In 14 patients undergoing hemodialysis, the intraocular pressure did not change significantly when measured at hourly intervals for 4 h. There was a loss in body weight because of fluid loss; also the Schirmer values decreased significantly at the conclusion of treatment. Blood osmolality decreased markedly in a linear fashion. The fluctuations of intraocular pressure during hemodialysis were likely dependent on the dynamics of dehydration and hypo-osmolality. Regulatory forces stabilized the intraocular pressure to such a degree that statistical significance in these fluctuations was not reached.