In females random X-inactivation and subsequent embryonic development cause a specific distribution of cell clones. This aspect can be seen in carrier women for different X-linked diseases. In such dermopathies the carrier women show striated skin affections following a system of lines, which has been described by A. Blaschko in 1901. An analogous pattern can be seen in the retina of carrier women for the X-linked ocular albinism. The fundus shows a partial involvement with a striated pattern diverging from the papilla. In X-linked cataracts carrier women have lens opacities with an irregularly radiated pattern as well as segmental cataracts. This finding is demonstrated in the isolated X-linked cataract, the X-linked chondrodysplasia punctata, and in Lowe's syndrome.