Oh, that. Yes.
Over on r/doctor_who someone wondered whether his sonic sunglasses or whatever they are couldn't just take a picture of the combination lock to send to Bill. That should be a thing.
I agree that was stupid. But they could have set up another way that means the Doctor/ Bill repeats the mistake made at the monastery in Extremis - when he tried to return his sight and was both weakened and pursued by Monks for it. (and he still remained blind) A certain next episode trailer (called
$1 tells me that a similar thing may happen, but on a world scale.
I'm writing a fan theory on the actually important role of the doctor's blindness and the possibility that it might not be ended... around 0:16 on that video it show the Doctor touching something, and yelling in agony with his eyes turning blue. There's also very faint images of the Monks in two scenes throughout Earth's timeline around him, which probably implies he's in their temple.