The authors reviewed the medical records of 36 patients in whom the nucleus or nuclear fragments were retained in the eye after cataract surgery. In 4 patients, there was no further surgery, and visual acuity deteriorated to counting fingers or worse (mean follow-up time, 14 months). Thirty-two patients underwent vitrectomy to remove the retained, unencapsulated nuclear material. Sixty percent (6 of 10) of patients in whom vitrectomy was performed after 3 weeks had chronic glaucoma on long-term follow-up, whereas this complication developed in only 18% (4 of 22) of patients in whom vitrectomy was performed in less than 3 weeks. Sixty-three percent (21 of 32) of vitrectomy patients had final visual acuity of 20/200 or better after removal of the retained nuclear fragments. The causes of the poorest visual outcome (less than 20/200) included 1 or more of the following: corneal decompensation, chronic inflammation, chronic glaucoma with optic atrophy, and retinal detachment.