'What If' a certain Geass user appeared?
It's a VN, thus multiple routes spread
At full Power, Geass of Absolute Obedience seems to require no direct eye contact.
Just target someone, and make sure you voice the command.
At least that's how I interpret it, cause otherwise I can't explain how the main character ordered everyone to forget him in a 100ft radius.
(think of how Rollo's geass affects directly your brain, or Mao is picking up stuff from your brain directly)