In a steampunk/futuristic world, the apprentices of a cyberneticist (ex: Dr. Soong from Star Trek: TNG) are involved in a serious accident that requires the use of prostheses in place of large parts of their bodies. Created by their mentor, the prostheses make use of a specific solution in order to maintain their complex processing power. When the apprentices are separated from him (and his notes), however, they aren't entirely sure how to replicate this solution but do come to understand how to implement blood in its place. Therefore, the apprentices are pretty much cyborg "vampires", minus the traditional curse.
I was curious, though:
Following in the theme of "synthetic vampires", would a byproduct of the cybernetic prostheses cause a mirror to not reflect their images, but allow them to still be visible to the average person? What would this side effect be and how would it cause this occurrence? If it is necessary for a reasonable answer, only obscuring the reflected image is fine. Other metallic/etc. objects with reflective properties should likely have the same issue mirrors do, but pools of water are not a major area of concern. Too, if something needs to be added onto the systems for an answer to work, I wouldn't mind as long as you explain it (for example, adding light absorption as a backup power system, but how would that cause the entire person to become invisible to mirrors alone, and wouldn't that be a better alternative to a solution based system? invisibility would be a last resort).
Please, try to keep magic out of this, as this leans more towards science fiction than fantasy. Edit: Magic would be defined as a power that comes from within a person or living and/or organic being, while technology grants power externally. For example, fire magic comes from the life force or specific energy/mana connected to a soul or spirit within a being, and the strength and size of the fire rely on just how much of this specific energy or strength is present within the individual. On the other hand, the ability to produce fire using a flamethrower does not count as magic, as it relies on some external, nonliving object's properties rather than the individual's abilities alone. Even though you pulled the trigger, you technically didn't light the already flammable gasoline with some kind of power within you, you just were a factor in the function of the object. I hope that cleared things up a bit.
Edit: I was thinking that the reflection would be invisible to everyone, including the cyborg, though I am curious as to why only the cyborg would not able to see itself. I realize this question gets a little impractical with the current criteria, so the current answers given are highly appreciated.
I am intrigued by Philipp's brilliant answer to a similar question regarding vampires of the magical sort, but I'd prefer answers regarding glass mirrors.
If you're curious about the solution/blood as a power source, here is an interesting related article from Wired.
Thank you for your help.