Serum, aqueous humour, and lens ascorbic acid levels were determined by high-performance liquid chromatography in cataract-, closed-angle glaucoma-, and aphakic patients. The total number of 108 patients were subdivided into different groups. In several groups the pre-operative serum and aqueous amounts were tested, whereafter patients in some groups were loaded with ascorbic acid orally. Finally, a second test was performed on samples taken during operation. It turned out that the ascorbic acid concentration mechanism in cataractous eyes needed more than 12 h for maximum reaction on the loading stimulus. The slow reaction is surprising compared to other species, and it may reflect an affection of the secretory process itself in this disease.