The authors examined 78 fellow eyes in patients aged 2.5-20 years treated for retinal detachment. The examinations were carried out in the course of the hospital treatment and 2-10 years after the discharge from the Ophthalmological Department. In the period of observation the progression of the vitreous changes was seen in 9 eyes and it took the form of appearance or increase of the fibrillar degeneration of the vitreous, the condensation of its basis and of vitreoretinal adhesions; it coexisted with the appearance of new pathological processes in the retina. During the hospital treatment the retinal pathological changes were seen in 30.8 p.c. of cases and in the late examinations in 41 p.c. The most frequently discovered degeneration was the lattice degeneration. The frequency of the fellow eye syndrome in the late examinations increased from 10.2 p.c. to 17.7 p.c. of the examined patients.