Re: What is the voltage/current of the output of a human eye?

That's an interesting question. The short answer is that the output potential of the photoreceptors within the eye is between 40 and 70 millivolts (.040 to .070 volt). However, the way the eye functions isn't strictly electrical, but electrochemical, based on the transfer of ions and alteration of the shape of optical pigments, so categorizing the signal as an electrical one isn't entirely accurate.

A good overview of the process, called phototransduction, may be found in this article at Wikipedia.