This study investigates the T lymphocyte role in the production of the specific immunosuppressive environment that occupies the anterior segment of the eye. Aqueous and peripheral venous blood samples were taken from 23 patients who were operated because of senile cataract. In all samples, T helper/T suppressor ratios were established and differences between aqueous and blood samples were investigated by t statistic and Mann-Whitney U test. We found significantly more T suppressor cell activity in aqueous humor than in peripheral blood (p<0.05). We think that high T suppressor concentration in aqueous humor plays an important role in the induction of the immunosuppressive microenvironment that occupies the anterior chamber of the eye.