The primary visual cortex, which is responsible for generating more complex images, is located deeper within the calcarine fissure of the occipital lobe, so intracortical stimulation is needed to stimulate these areas effectively. Intracortical stimulation uses an electrode that goes deeper into the brain to more effectively stimulate the primary visual cortex, as opposed to trying to work only from the surface of the brain, which can cause unintended visual signals, pain, and damage to the nervous tissue. For patients with glaucoma and optic nerve atrophy, existing retinal prostheses are not an option since the optic nerve is damaged, therefore a prosthesis using cortical stimulation is a remaining hope to offer some vision function. A cortical visual prosthesis is a promising subject of research because it targets neurons past the site of disease in most blind patients. However, significant challenges remain such as reproducibility in different patients, long-term effects of electrical stimulation, and the higher complexity of visual organization in the primary visual cortex versus that in the retina. Another site of research for a vision prosthesis using cortical stimulation is the optic nerve itself, which contains the nerve fibers responsible for the complete visual field. Research is still ongoing in this area and the small size of the optic nerve and the high density of nerve fibers are continuing challenges to this approach Cortical stimulation mapping vs. transcranial magnetic stimulation Cortical stimulation mapping (CSM) is considered the gold standard for mapping functional regions of the brain to create a presurgical plan that maximizes the patient's functional outcome. The history of beneficial outcomes and the amount of information already established about the CSM technique makes it advantageous in clinical and research applications. However, because it has the drawback of being an intraoperative technique, there is growing debate about its status as the preferred method. Instead, transcranial magnetic stimulation (TMS), a new procedure that does not carry the same amount of surgical risk, is being considered. Transcranial magnetic stimulation has been gaining increasing interest as an alternative tool for studying the relationships between specific cortical areas and brain function, particularly because its non-invasive nature is advantageous over CSM. Additionally, because of the increasing body of research focused on investigating the many medical uses of TMS, it could eventually have more applications than CSM. For example, this procedure been successfully used to measure the speed of conduction in central motor pathways, making