Garvin's ability was FAQ'ed to explicitly clarify that you may spend a focus token to change zero eyeballs.
It used to be that way. The latest FAQ uses a different wording:
When attacking, players may spend focus tokens or target locks and elect not to modify any attack dice. When defending, players may spend focus tokens and elect not modify any defense dice and may spend evade tokens to add evade results in excess of the number of hit and critical hit results.
The phrase " may ... elect not to modify any attack dice " does not mean that you modify zero dice. It means you do not modify in the first place.
Edit:
Not sure if that changes the ruling. Only pointing out that the FAQ changed.
That is a different issue. This ruling would be relevant if someone wanted Keyan to remove stress and NOT change eyeballs to hits. That ruling is very interesting, because it is actually contrary to the Core Rulebook in the case of spending focus tokens. The rulebook requires that if you spend your focus token, you change ALL of your eyeballs to hits. The FAQ (which supercedes) states that you don't have to change all of the eyeballs.
In any event, for my previous post, the pertinent section of the FAQ is on page 7 directly next to Garven:
So, there has been no change to the FAQ regarding spending a focus token when zero eyeballs are present.
Edited by MajorJuggler