Among the various forms of juvenile macular degeneration, one can distinguish those that primarily involve: 1. The neuro-epithelium: Stargardt's disease; dominant juvenile degeneration; central or pericentral pigmentary retinopathy, progressive dystrophy of the cones and cystoid macular oedema. 2. The pigment epithelium: vitelliform degeneration of the macula, fundus flavimaculatus, Sjögren's reticulated pigmentary dystrophy, butterfly shaped pigment dystrophy of the macula and grouped pigmentation of the macular region. 3. Bruch's membrane: the hyaline dystrophies or drusen of the lamina vitrea and dominant progressive foveal dystrophy. 4. The choroid: central areolar atrophy of the choroid and Sorsby's pseudo-inflammatory dystrophy. -- All these macular heredo-degenerations are characterized by the fact that they are bilateral and symmetrical. For diagnosis and differential diagnosis not only the ophthalmoscopic appearance is important, but also the examination of the visual functions, which must include an electroretinographic and electro-oculographic examination, as well as the genetic study of the affected families.