Collagenic formations occur increasingly with age in the retinal periphery of adults. They grow from the vitreous cortex and from the vessels. In extensive growth they form intraretinal networks. Different inflammatory, degenerative and malformative diseases of the retina lead secondarily, and this already in young persons, to an extensive development of such structures. The name 'peripheral retinal sclerosis' is proposed for such alterations in the peripheral retina. Since the peripheral retinal sclerosis occurs at the same areas where the symptom 'white with pressure' is found, one believes that these formations are its organic substrate. The opacification is thought to be a consequence of the stretching of these collagenic formations during the indentation. Deposition of lipids in these formations can show the symptom 'white without pressure'.