I remember there was news of a bionic eye surgeons made to allow blind people to effectively see a year or two ago.

Also the nervous system controlled prosthetic limbs linked above.

The only two problems are that they are ridiculously expensive and are nowhere near to the point they are here. The prosthetic arms we have don't enhance your strength or whatever, they just allow you to function like a normal human being again. The only prosthetic that can really be better than the organic part is prosthetic legs, as they won't get tired like normal legs will, allowing a person to run further than people with normal legs.