In Mass Effect 2, Shepard's physical appearance (especially when you decided to go Renegade) could end up changing pretty drastically, though you could permanently reverse it if you chose to.
Does this behavior continue in Mass Effect 3? I'd like to know so I can customize my character's appearance accordingly if this is going to happen again, especially if she's going to end up with Terminator eyes...
Yep. Renegade sheps will see the same trademark fire red facial scars and red eyes.
Random screenshot:
However, the scars and glowing eyes are based on your current, ME3 alignment. Since even a full renegade bar from ME2 only amounts to a token chunk of Renegade points, Shepard will always have minimal scarring at the start when imported, regardless of whether you upgraded the Med Lab in the previous installment.
Consider it a result of the 'low stress environment' that is an Alliance brig awaiting court martial.
A message soon after you start the game appears when you are upgrading you and your squads powers. This message states that (assuming you are going renegade) if you continue to be harsh and cause stress, the scars derived from your implants will start up again.
It's true. Apparently, Bioware is consistent about it as well. In Knights of the Old Republic this also happens. The moral of the story is, if you accept the dark side, whether it was long long ago, or far into the future you'll end up getting scars and red eyes.
It's been confirmed that Renegade Players get the trademark scars like in ME2. If you import your character they should keep the scars too.
Sounds like Shepard keeps the glowing eyes (see On Orbit's post) as well though I haven't personally confirmed this (I'm Paragon).
