If this can be done inside the eyes, it can be done outside the eyes, as a removable eyeglasses like thing.

This is why cyberpunk never really made sense to me. Why remove the choice of putting something on or off? Okay there is an advantage of never forgetting it at home, still. Gibson's razor blades implanted under the fingernails sound cool until you realize you just gave up the option of ever being allowed on an airplane for example.

Oh, and sometimes I hear horror stories that when people wear diamond rings for decades and it becomes unremovable from their fingers, and some criminal mugs them, they just cut of the finger. Extrapolate from here...