To test the hypothesis that cataract extraction in glaucomatous eyes improves overall sensitivity of visual function without affecting the size or depth of gl aucomatous scotomas. Experimental study with no control group. One hundred fifty -eight eyes (of 140 patients) from the Advanced Glaucoma Intervention Study wit h at least two reliable visual fields within a year both before and after catara ct surgery were included. Average mean deviation (MD), pattern standard deviatio n (PSD), and corrected pattern standard deviation (CPSD) were compared before an d after cataract extraction. To evaluate changes in scotoma size, the number of abnormal points (P < . 05) on the pattern deviation plot was compared before and after surgery. We described an index (“scotoma depth index”) to investigate c hanges of scotoma depth after surgery. Mean values for MD, PSD, and CPSD were-1 3.2, 6.4, and 5.9 dB before and-11.9, 6.8, and 6.2 dB after cataract surgery (P ≤. 001 for all comparisons). Mean (±SD) number of abnormal points on pattern deviation plot was 26.7±9.4 and 27.5±9.0 before and after cataract surgery, re spectively (P=. 02). Scotoma depth index did not change after cataract extractio n (-19.3 vs-19.2 dB, P=. 90). Cataract extraction caused generalized improveme nt of the visual field, which was most marked in eyes with less advanced glaucom atous damage. Although the enlargement of scotomas was statistically significant , it was not clinically meaningful. No improvement of sensitivity was observed i n the deepest part of the scotomas. To test the hypothesis that cataract extraction in glaucomatous eyes improves overall sensitivity of visual function without affecting the size or depth of gl aucomatous scotomas. Experimental study with no control group. One hundred fifty-light eyes (of 140 patients) from the Advanced Glaucoma Intervention Average mean deviation (MD), pattern standard deviatio n (PSD), and corrected pattern standard deviation (CPSD) were compared before an d after cataract extraction. To evaluate changes in scotoma size, the number of abnormal points (P <. 05) on the pattern deviation plot was compared before and after surgery. We describe an index (“scotoma depth index”) to investigate c hanges of Mean values ​​for MD, PSD, and CPSD were-1 3.2, 6.4, and 5.9 dB before and -11.9, 6.8, and 6.2 dB after cataract surgery (P ≤ .001 for all comparisons). Mea (± SD) number of abnormal points on pattern deviation plot was 26.7 ± 9.4 and 27.5 ± 9.0 before and after cataract surgery, re spectively (P = .02). Scotoma depth index did not change after cataract extractio n (-19.3 vs -19.2 dB, P = .90). Cataract extraction caused generalized improveme nt of the visual field, which was most marked in eyes with less advanced glaucom atous damage. No significant effect was found in scotomas improvement of sensitivity was observed in the deepest part of the scotomas.