In 20 patients with retinal detachments caused by the impact of a soccer ball, the interval between the injury and the diagnosis of retinal detachment was less than one month in ten cases and less than one week in four cases, suggesting that the retinal breaks occur at the time of injury. The most common breaks were superotemporal dialyses and round or oval holes. Macular damage was common. Nineteen of the 20 retinas were reattached surgically, Final visual acuities were 6/12 (20/40) or better in 12 cases, but worse than 6/60 (20/200) in five patients, all of whom had total long-standing retinal detachments or severe traumatic maculopathy. In 48 male patients with X-chromosome-linked juvenile retinoschisis, there was a high proportion with refractive errors. Vitreous veils occurred in 22 patients (47%) and macular lesions were the most common finding. In younger patients the small macular cysts were arranged in a radial pattern and separated by yellow septa. There were also fine radial folds in the internal limiting membrane in most cases. Peripheral retinoschisis was found in 19 patients (39.6%). In eight patients who underwent photocoagulation in one eye, the retinoschisis had not progressed in either eye after a mean follow-up period of 49 months. Retinal detachments occurred in five eyes (5.2%) of the youngest boys with extensive retinoschisis. In a series of 1,000 consecutive cases of rhegmatogenous retinal detachment, 9.8% were the result of nontraumatic retinal dialyses. Most o(97%) of the nontraumatic retinal dialyses occurred in the inferotemporal quadrant. Multiple dialyses occurred in 32% of the patients. In a series of 100 cases, the dialyses were bilateral in 37. A familial pattern was demonstrated in eight pedigrees. Surgery, including cryotherapy or diathermy, scleral infoldings, silicone implants, and drainage of subretinal fluid, reattached 97 of the retinas but the visual acuity results were often unsatisfactory.