MSH: A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.,JABL: Total or nearly total blindness present at birth or shortly thereafter. The fundus may appear normal at birth but pigmentary changes similar to those seen in retinitis pigmentosa take place later in life. Ocular complications may include atrophic changes, cataract, keratoconus, absence of the rods and cones, hyperopia, microphthalmia, optic disk edema, nystagmus, photophobia, and Enophthalmos may occur due to digital self stimulation. Some patients show psychomotor retardation, sensory hearing loss, hypotonia, and various neurological disorders.