You'd probably prefer that doctors restore lost sight or hearing by directly repairing your eyes and ears, but Rice University is one step closer to the next best thing: transmitting info directly to your brain. It's developing a flat microscope (the creatively titled FlatScope) that sits on your brain to both monitor and trigger neurons modified to be fluorescent when active. It should not only capture much more detail than existing brain probes (the team is hoping to see "a million" neurons), but reach levels deep enough that it should shed light on how the mind processes sensory input. And that, in turn, opens the door to controlling sensory input.
FlatScope is part of a broader DARPA initiative that aims to create a high-resolution neural interface. If technologies like the microscope lead to a way to quickly interpret neuron activity, it should be possible to craft sensors that send audiovisual data to the brain and effectively take over for any missing senses. Any breakthrough on that level is a long way off (at best) when even FlatScope exists as just a prototype, but there is some hope that blindness and deafness will eventually become things of the past.