Tracing the shape of letters on the surface of the brain using an implant that electrically stimulates neurons enabled people who have lost their sight to “see” the letters
Source:
https://www.newscientist.com/article/2243608-people-see-letters-traced-on-their-brains-surface-by-an-implant/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home