After reading the X-wing FAQ, some confusion formed. The question said "Can Garven Dreis spend a focus token to modify dice if he didn't roll any focus symbols". The answer was "Yes". This has caused my dad (the rebel player) to believe that he can spend the focus token to change focus icons AND blanks into hits. For example: you roll three attack dice. You roll one hit and two blanks. You spend the focus token and the two blanks become hits and the focus token moves to a different ship. I think it means that even if you don't roll focus icons, you can still spend it so that you can pass it on to another ship without changing your results. For example: you roll three attack dice. You roll one hit and two blanks. You spend your focus token. While it doesn't change any of the dice, Garven's ability lets you move the focus token to another ship of yours.

Your interpretation is correct. Your dad is living in a different universe.

EDIT: If you could change your blanks to hits with a focus token, there wouldn't even be a point to rolling the dice. They would all just be hits.*

*Not strictly true because you could roll one or more Criticals, but I wanted to highlight the absurdity.

This will give you joy to tell your dad that you are correct.

*beat me to it a4rino

Garven can spend his focus token to alter 0 focus results, if he wishes. No alteration is made to the dice, but he has still spent his focus token.

Yeah it just means that he can "spend" the token - and thus pass it on - even if he had no eyeball results to change. He's basically spending it and getting nothing in return, just so he's able to pass it along. Sorry, dad.