The heads-up displays would not be physically implanted in our eyes. It would be part of that cell phone implant you mentioned, most likely on or in the brain. It would merge display information into the data sent by our eyes along the optical pathways into the brain. I read an article recently, about a quadriplegic who received a brain implant on the cerebral cortex, allowing him to move robotic arms to serve his needs (like feeding and drinking for himself), just by thinking what he wanted the robotic arms to perform. The cerebral cortex is responsible for higher brain functions like thought, reasoning and memory. These devices are being tested now on humans, and after FDA approval we will be able to have these cool new gadgets.
Can I get one which identifies people that post on FR so I know to avoid them as they're likely to have guns that could accidentally go off and kill me?
/sarc