She had a much better bedside manner than he did. That was one thing he would readily acquiesce to in regards to such things. If he hadn't been personally aware that he was not good at bedside things, then the amount of times others pointed it out would definitely have enlightened him by this point. Hannah was a much more cmpassionate and kind person than he was.
He kept a careful eye on her as she administered the second potion, and he grimaced in mute sympathy at her expression. He hated those disgusting tasting ones too, though they could be fun to give to someone you rather did not like. If you knew your potions well enough, as he did, you could prescribe something vile to someone accureately but purposefully.
His squeeze in return was firm and reassuring. "Of course," he told her. "I think your vision will return shortly, but if it doesn't, there are still some options I can take easily." Other potions and such, or a couple of charms. But there was confidence in his voice that this would work.
"Do you have any idea of who might have drugged you?" he asked as he slipped the empty vial back into his pocket and went to grab the vials of blood so he could store them properly until he could contact the aurors.