Neil Harbisson
Harbisson was born with a condition called achromatopsia that allows him to only see in gray-scale. He has a specialized electronic eye that allows him to hear perceived colors as sounds on the musical scale. An antenna is implanted in his skull that allows him to receive the sounds and phone calls directly into his head.
Jens Neumann
He became the first person to receive an artificial vision system. This system allows him to see lines and shapes. This is possible because the eye is connected directly into his visual cortex through brain implants.