Neurofibromatosis type I is multisystem disorder with myriad manifestations, many of which involve the eye. Diagnostic findings include neurofibromas, lisch nodules, café-au-lait macules, freckling, optic pathway gliomas, and skeletal dysplasia. The responsible gene and its protein product, neurofibromin have been identified. Advances have been made in the understanding of the functions of neurofibromin. This has allowed better understanding of the many manifestations and will help identify potential treatments.