I think that one of the major hurdles to BCI is the mechanism of connection. When electrodes are connected to neurons they have a tendency to be destroyed. However, one might imagine the development of sophisticated electromagnetic equipment which might suitable focus and modulate "receptor pathways" in the brain. This seems far off. Eyes are convenient sensory organs to utilize for input. Getting directly to the brain seems more like trying to manipulate electron flow in a PCB without removing the external enclosure. (not to say that's impossible, just not as easy as cutting a trace and soldering in a connection)