Would you prefer cybernetic? Robotic? Mecha? SUPAR GEKIGANGER GUNDAMIAN KAISER eys?
I know what you mean, but all the alternatives seem to sound pretty much the same. I wouldn't worry too much, though - the important bit is that they work. Besides, had I a bionic eye, I'd gladly refer to it as a cyber-eye and preach about the Machine Spirit and the downfall of fleshies.