Your new knee isn’t as good as the old one except for the fact that it will become upgradeable rather than age. It’s more beautiful, too. You are rich enough that it’s easy to find a surgeon to replace the other one.
You could get contact lenses; you have no genetic tendency to serious vision issues; artificial retinas are far from equivalent. There’s something otherworldly in their sleek blackness. It’s almost the last thing you see before the surgeon implants them.
There are many more things for him to do. It’s a Golden Age of prosthetics.
A couple years later he surprises you by breaking down despite a moral code almost entirely shaped by ambition and curiosity. You remind yourself he was a more reliable choice than one of the true sociopaths in your shortlist, as he tells you in near-tears how nothing you’re doing will change the fact that your brain is getting older — despite the treatments, despite the care, faster than it would have, even, without the physiological shocks of surgeries and implants — and therefore, you.
Once his ranting is done you use your voice synthesizer (your voice, you have found, the only true improvement you have gotten from your implants, not that it mattered, not that it was the point) to instruct your computer to show him the latest findings from your technology scouts. Finally, at long last, while neural implants are still in their infancy there are already parts of the brain that can be replaced with survivable functional loss.
The surgeon falls silent. Your vision isn’t good enough to be sure, but you can hear the way his breath hollows out. When greed becomes sour and pride finds its limit and falters – there’s always horror. He will do it.
You would smile if you still had something to smile with.