Powering implants within the brain is another big issue. Wirelessly charging the devices seems to be the best route for those embedded within the brain itself. Transmitting enough energy, without heating up the tissue, is tricky but can be done: one team recently developed an antennae that is the size of the grain of rice and can receive energy through several centimetres of tissue, without exceeding the safe threshold of electromagnetic radiation.

Step 7: Hack your senses?

For the foreseeable future, these devices will only be used to treat people with severe disabilities. Chips to allow people to operate robotic limbs have already shown some success in human trials, while Nirenberg hopes to test her artificial retinas on humans within the next couple of years. The US Defense Advanced Research Project Agency (Darpa), meanwhile, hopes to test devices for amnesia by 2019.

Some futurists even hope that implants could confer “super-human” powers on able-bodied people. As a taste of what might come, one journalist recently hacked his hearing aid so that he could hear the WiFi signals as he walked through London. It’s not inconceivable that someone with a cochlear implant could do the same – or even use it to eavesdrop on conversations in another room.

Realistically, it is unlikely that healthy people would undergo surgery for recreational purposes, but who knows? Restoring sight to the blind or helping the paralysed to walk were, after all, beyond our imagination only a few decades ago.

If you would like to comment on this article, or anything else you have seen on Future, head over to our Facebook or Google+ page, or message us on Twitter.