This is why a traditional screen has fewer ethical issues than a brain or eye implant.
"There was truth and there was untruth, and if you clung to the truth even against the whole world, you were not mad" (Part 2, Chapter 9).
"'You can turn it off!' he said. 'Yes,' said O'Brien, 'We can turn it off. We have that privilege'" (Part 2, Chapter 8).
In the latter quote, O'Brien is referring to the Inner Party's exclusive privilege to turn off the two-way screen. Such a situation could be even worse than Orwell imagined, if operating on a chip implanted in the brain or eye rather than a traditional screen. We will return to this when discussing the privacy aspect of the argument.
First of all, out of innate respect for our own bodies, humans have a vested interest in minimizing rather than maximizing the need for surgery. The need for surgery will never be zero, but it can be minimized. When your phone or laptop breaks or becomes too obsolete for the next software update, you can replace it without surgery. If a device were implanted in your brain or eye, you would need additional surgery to replace obsolete or damaged hardware.
A popular argument concerns the use of robot appendages in prosthesis, at least initially as a remedy for injury. (This use of cybernetics may or may not spread to more general use closer to the brain.) For a familiar science fiction reference, think RoboCop. This more benevolent use of cybernetics may be ethically used as a temporary bridge toward stem cell medicine. When a soldier loses his arm or leg in battle, however, the best possible remedy would be to regrow a new arm or leg, biologically.
Of course, humans do not naturally regrow limbs, as starfish do. We are, however, close to developing the level of stem cell technology that will allow us to achieve the same effect. Such regrowth, though artificial, is nevertheless biological as opposed to robotic. Once the procedure is complete, the new limb would naturally heal from lesser subsequent injuries, never requiring a manufacturer replacement as a robotic limb might.
A man loses his left leg to landmine, and when stem cell technology gives him a new leg, it heals on its own from a small cut falling off his porch. A woman loses her right hand in a work-related accident, and when stem cell technology gives her a new hand, it heals on its own from a paper cut. These scenarios and more will be possible when future technology refines the use of stem cells to regrow appendages or internal organs. Based on the natural ability of flesh to heal, this will be a better alternative over robotic parts.
Traditional screens allow easier access to reality, in that our natural senses continue to perceive the boundaries of the screen. Even with a virtual reality helmet, our sense of texture perceives the helmet, despite the more complete immersion of our eyesight. When looking through a camera on the Moon, for example, seeing the screen or feeling the helmet reminds you that you are not actually on the Moon. If a chip were implanted in your brain and interacting directly with your mind, it would only increase the risk of losing track of the threshold between virtual and actual. It would also increase the completeness or extent to which that boundary can be forgotten.
We now return to the issue of privacy, so keenly alluded to George Orwell's Nineteen Eighty-Four. In the novel, the Party uses two-way screens to spy on everyone. Only Inner Party members, such as O'Brien, are able to turn the screens off. By replacing these screens with chips implanted in the brain, or even in the eye to access the brain via the optic nerve, the Thought Police would have a direct and more comprehensive access to the mind of every individual. Under that scenario, protagonist Winston Smith would not have lasted even as long as he did! With implanted chips, Nineteen Eighty-Four would be an even more depressing book albeit shorter book!
Even with traditional screens, there are privacy concerns based on corporate and government entities accessing and analyzing browser histories. Take solace that they can only see your online history and not your mind per se. That is a good thing!
Even though Nineteen Eighty-Four, Brave New World, and Anthem (by authors George Orwell, Aldous Huxley, and Ayn Rand, respectively) are fictional books, that is no excuse to dismiss the warnings they contain. Countless analyses have been written as to how something like these fictional scenarios could indeed come to fruition, and a full review of those analyses would be outside the scope of this article.
Objection 1: "Aren't you tired of coursework and having to practice new skills? Wouldn't it be nice just to download knowledge into your brain instead?"
Part of what makes us human is that we learn like humans, rather than downloading like machines. Would the Olympic Games really be as awe-inspiring, if not for the assurance that every athlete had to practice across years of trial and error?
More importantly, this objection ignores the likely behavior of those in charge, due to selfish human nature combined with the temptations of authority. If brain-implanted chips were in wide use, the more likely scenario is that the Inner Party (so to speak) would use them to erase all quote-on-quote "useless" knowledge, making the Outer Party and the Proles (as it were) more obedient and "perfect." The histories of technology and human authority make it unlikely that you could simply download knowledge of your choice, with your privacy and individuality being respected.
Objection 2: "Given the destruction of embryos and the preciousness of all human life from conception to natural death, how is stem cell technology still a better alternative to robotic limbs?"
Induced pluripotence renders the destruction of embryos unnecessary, and is a highly active area of research for this very reason. Without destroying any embryos at the beginning of the process, the end results remain the same.
Extract an adult bone marrow stem cell. Run that cell through a series of biochemical treatments until it behaves like an embryonic stem cell. Grow and multiply it in a laboratory. Use it just as you would use an embryonic stem cell, minus the ethical issues.
Objection 3: "What about the life extension of transferring one's mind into a machine?"
Machines do not last forever, either. Ask anyone involved in manufacturing, for example. One of the major expenses, when running a factory, is having to replace broken robots on the assembly line.
The best of hope of life extension, and the one that would preserve your life in essentially the sense that you are accustomed to it, is to do it by using stem cell technology to slow down aging. In addition to stem cell technology and induced pluripotence as explained above, this will require injections of telomerases (DNA repair enzymes that work at either end of a chromosome molecule). The means to purify such enzymes are already known, however, so the need for them is not much of an obstacle.
Objection 4: "The same mathematical models can describe both machines and biological brains. Given that, why should or would we and our posterity act upon the above ethical arguments?"
First of all, those mathematical models are approximate rather than exact. An exact model would have to describe the system down to a molecular level, at which point the physical substance or chemical makeup would indeed matter.
Second but more importantly, physical similarities never by themselves negate any ethical argument. The DNA of cattle is relatively similar to human DNA, owing to the fact that both are placental mammals. This does not change the fact that cannibalism is intrinsically unethical, while beef is not.
Objection 5: "Wouldn't it be cool to transmit thoughts directly to others, without having to use language as a medium?"
The information would be disorganized, cluttered, and essentially useless to the other person. Humans not only use language to transmit information, but also to organize it.
Thoughts in and of themselves are more or less random. They are arranged in ways that only ever make sense to that respective individual. There is a reason why "stream of thought" or "stream of consciousness" is an expression, and it is not because thoughts are well organized!
Objection 6: "Why argue against the inevitable?"
It is not inevitable when enough people are aware of these serious ethical issues. Some may fall into it, but not those who are aware of the ethical problems. Technology is driven by demand, after all.
Objection 7: "What about the practically unlimited knowledge of the Internet?"
You already have access to it, via traditional screens. Your brain and mind, however, are the final bastions of any real privacy. Even the Deep Web is monitored, albeit less closely than the Surface Web. Big Brother is always watching what you do online.
Objection 8: "I'm into organic gardening (or any other naturalistic hobby). Why not look up the latest techniques on an implanted lens?"
This objection assumes, wrongly, that the rejection of eye or brain implants merely constitutes a gut reaction to the unnatural. For the better reasons for said rejection, see the original argument and all other objections answered above. See also the acceptance of traditional screens, which are in fact just as artificial, in the very same argument.
Quod Erat Demonstrandum.