Re: Harvesting spare static electricity
I'd have thought a better solution would be those power cells that metabolise glucose.
Good idea for implants in blood-perfused tissue, but the surface of an eye is not well-supplied with blood or glucose.
The best way for an eyeball implant would probably be photovoltaic ("solar power"). Eyeballs are well supplied with light, at least while you are awake. Transparent solar cells can be made (indeed, large ones are being installed as windows on "green" skyscrapers).
Another way would be wireless power (I'm assuming only microwatts are needed). You'd need to wear a power transmitter elsewhere on your person if continuous power was needed. You might be able to scavenge power from a 21st century environment if continuous power was not vital. (ie, parasitise off WLANs and mobile phones).
Yet another way would be piezo-kinetic power scavenging (as in the Seiko Kinetic watches). Again I can see that working much better for implants in other parts of the body.