Complex sentence: Leber's congenital amaurosis is an inherited disease resulting optic atrophy and secondary severe vision loss or blindness that was first described by Theodore Leber in the 19th century.
Split into simpler sentences: Leber's congenital amaurosis is an inherited disease resulting in optic atrophy and secondary severe vision loss or blindness. It was first described by Theodore Leber in the 19th century.