We analyzed more than 4 consecutive measurements of the central area of the visual field in 1,004 eyes of 533 subjects with various types of glaucoma as diagnosed by the Octopus 201 and its examination program No. 31. We used a non-repeated analysis of variance to determine the statistical relationship between the mean sensitivity measurements for individual quadrants of the central visual field. We made the series of measurements used in this statistical analysis during repeated examinations that took place over a follow-up period of 1 year. Out of 1,004 eyes, 53 eyes (5.3%) were shown to have an improved mean sensitivity of the central 30 degrees of the visual field. We adopted the degree of sensitivity improvement [(final mean sensitivity - initial mean sensitivity)/follow-up period] as the indicator of the degree of reversibility in the central visual field to determine which factors might influence changes in the visual field. In patients under 50 years of age, who were at an early stage of the disease, as opposed to those over 50 years of age, who were at an intermediate or advanced stage of this disease or who had undergone reduction of intraocular pressure, a relatively high degree of sensitivity improvement was more frequently observed. In the cases with primary open angle glaucoma which includes low tension glaucoma, we think treatment for abnormality in the aqueous humor dynamics is very important. We concluded, that the reversibility of the central visual field defect in glaucomatous eyes is possible, though it can only be clearly detected by careful follow-up examinations employing computerized perimetry.