Tears from patients with chronic allergic conjunctivitis were analyzed with flow cytometry to determine the function of the T lymphocyte-related immunological reactions in the disease pathogenesis. Twenty-eight patients and 22 normal volunteers were studied; tears were obtained with capillary tubes. T helper/T suppressor ratios and the percentages of HLA DR+, CD23+, and CD3+ cells were significantly higher in patients than in controls. This study provides support for the hypothesis that chronic allergic conjunctivitis results from T lymphocyte-related immunological reactions. (C) 1997 Japanese Ophthalmological Society.