We measured glare produced by opacified posterior capsules before and after neodymium-YAG laser posterior capsulotomy. In many eyes, particularly those with visual acuities of 20/200 or worse, glare threshold could not be determined. In 32 eyes with measurable preoperative glare, the median glare threshold improved from 45% to 12% and median visual acuity improved from 20/60 to 20/25. For 56 eyes the median postoperative glare threshold was also 12% and the median visual acuity improved from 20/80 to 20/25. Forty eyes achieved postoperative visual acuities of 20/25 or better, but in 16 eyes other ocular conditions limited visual acuity to 20/30 or worse. Glare and visual acuity were correlated preoperatively and usually improved concomitantly. One patient in whom wrinkles in a clear capsule produced streaks around bright lights had a glare threshold lower than other types of opacities. Capsulotomy improved the glare threshold and relieved the symptoms.