Objective: To investigate the relationship between tear volume and tear menisc us curvature by means of the video meniscometer. Methods: Eleven eyes of 11 pati ents with severe dry eye were studied (all female; mean ±SD age, 66.2 ±7.7 yea rs; 7 left eyes and 4 right eyes), each of whose puncta had been therapeutically occluded. Four instillations of balanced salt solution were given at intervals of 1 minute in each studied eye, with the concentration increasing in 5-μL ste ps from 5 to 20 μL. Before and after the instillation of balanced salt solution , tear meniscus changes were recorded by video meniscometer and radius of the me niscus was calculated from the printed images by means of the concave mirror for mula. Results: The mean radius of the meniscus increased linearly with increased drop volume (r 2=0.65, P < 0.001), with mean±SD radius values of 0.24±0.08 mm at baseline and 0.48±0.13, 0.62±0.13, 0.84±0 .26, and 1.00±0.32 mm after separate instillations of 5, 10, 15, and 20 μL of balanced salt solution, respectively. For each subject, a significantly differen t slope defining the relationship between instilled volume and meniscus radius w as seen (0.016-0.063 mm/μl; mean±SD, 0.039±0.015 mm/μl), which was thought to depend on the difference in capacity of the fluid reservoir over the ocular s urface. Conclusions: This study confirmed that the volume of instilled eyedrops is linearly related to the resulting radius of the tear meniscus, suggesting tha t this radius is a useful measure in monitoring the tear volume. This is likely to have implications both for dry eye diagnosis and for confirming the efficacy of punctal occlusion in this condition. Methods: Eleven eyes of 11 pati ents with severe dry eye were studied (all female; mean ± SD age, 66.2 ± 7.7 yea rs; 7 left eyes and 4 right eyes), each of whose puncta had been therapeutically occluded. Four instillations of balanced salt solution were given at intervals of 1 minute in each studied eye, with the concentration increasing in 5-μL ste ps from 5 to 20 μL. Before and after the instillation of balanced salt solution, tear meniscus changes were recorded by video meniscometer and radius of the me niscus was calculated from the printed images by means of the concave mirror for mula. Results: The mean radius of the meniscus increased linearly with increased drop volume (r 2 = 0.65, P <0.001) with mean ± SD radius values ​​of 0.24 ± 0.08 mm at baseline and 0.48 ± 0.13, 0.62 ± 0.13, 0.84 ± 0.26, and 1.00 ± 0.32 mm after separate instillations of 5, 10, 15, a nd 20 μL of balanced salt solution, respectively. For each subject, a significant differen t slope defining the relationship between instilled volume and meniscus radius w as seen (0.016-0.063 mm / μl; mean ± SD, 0.039 ± 0.015 mm / μl) , which was thought to depend on the difference in capacity of the fluid reservoir over the ocular urface. Conclusions: This study confirmed that the volume of inlimed eyedrops is linearly related to the resulting radius of the tear meniscus, suggesting tha t this radius is a useful measure in monitoring the tear volume. This is likely to have both both for dry eye diagnosis and for confirming the efficacy of punctal occlusion in this condition.