Poor vision was not one of the known consequences of space travel, as far as Mark Watney knew, but it couldn't be denied that his eyesight had gotten considerably worse. It had been over six months since that cold morning in Houston, and life was considerably different now. Some things always remained the same, however, and when he'd failed his vision screening at his recent driver's license renewal, he had been forced to confront the fact that there was something wrong.

He hadn't really noticed any issues while driving; he thought his distance vision was about the same. But if he really thought back on it, this vision problem wasn't anything new. He'd needed to push his laptop back further than he was used to, back in the Hab. Even on Hermes, he could remember squinting and holding his tablet further away from his eyes than was normal for him, to bring things into focus. He'd attributed that to the weirdness of space travel, the way even the slightest bit of moisture in your eyes messed with your vision in low gravity.

But there was obviously more to it than that. His vision had deteriorated a shocking amount, now that he thought about it. It was more than a little bit scary to contemplate the future, if something couldn't be done. What if he lost his vision entirely? His heart started pounding, as a rare panic attack threatened; suddenly, he was right on the verge of losing control, as he gripped his hands tightly together. His breathing was fast and shallow, as his field of vision narrowed and the edges became frayed. How would he live without his eyesight? Never see the faces of the people he loved? It would be like getting left behind, all over again.

Relax. He forced himself to take ten deep breaths. One.

Don't think about it right now. Alone. Forever.

His clenched hands were shaking a bit, now. Not good.

Deep breaths. Two. Relax, he told himself. They have science for shit like this. I'm not going to go blind. Another deep breath. Relax. Three.

Minutes went by, as the panic attack subsided. He forced his hands to relax their grip.

He usually did not use the small, round computer that Oaiea had given him, when he was in public, but right now he needed the distraction. Anyway, there was no one here, in the optometrist's exam room, where he awaited his results. He circled through menus, re-reading his recent communication log with his friend. It calmed him down. There was a list of word associations he could work on. Some pictures that Oaiea had taken, stills from the TV shows she was watching; explaining the finer points of Game of Thrones might have to wait until he could think straight again.

Finally. There was the doctor. Sophia had recommended her. Dr. Nguyen had a nice, friendly businesslike manner about her, and thankfully, no hint of fangirl adoration or recognition at all, really. He knew that she knew who he was, but he still vastly preferred it when people didn't bring it up. Taking another deep breath, he braced himself.

"Okay, Mark. Oh, wow, you look really worried." She shook her head at him, smiling. "You're fine, Mark."

He grinned at her, ruefully. "I am?"

"Absolutely." Dr. Nguyen gave him another reassuring smile. Did he really look that freaked out? Apparently he did.

"Then what is going on? Why did I fail my vision screening? The more I think about it, the more that I realize that my vision has been going bad ever since I was on Hermes. Maybe even before that."

"You have presbyopia, Mark."

Presbyopia? "It sounds familiar," he managed to say. It called up a memory from when he was in college. Something his dad had said to him, when he'd first started wearing glasses. Did his dad have presbyopia? He was pretty sure that he was remembering correctly. "My dad has that, actually. I think so, anyway. Is it genetic?"

"No," she smiled, "it's just a normal, natural thing that happens as you age. The muscles around your lenses lose their elasticity, and make it more difficult to control your close-up focus."

"I'm going to need glasses, I take it?"

"Yep," she nodded, handing him a prescription. "There's other ways of dealing with it, as well. You could get laser surgery to create monocular vision, or any number of other options, really. But most of those options are going to require that you wear prescription lenses for at least six months while a baseline is established."

"Oh well," he quipped, "new glasses might be a good disguise."

She smiled. "Right here," she tapped the place on the page that said +2.00, "is the part of your prescription that indicates what strength your bifocals need to be. If you'd like to get some non-prescription reading glasses from the store, plus-twos are what you need."

"Wait. Did you just say that I need bifocals?!" Those were for old people, right? Old people like his dad? His dad, who'd gotten bifocals when he was... exactly Mark's current age.

Shit.

x x x

He'd fallen asleep again. Pathetic, he told himself. It was, he checked the time, half-past eleven, and the credits were rolling on the movie that he and Sophia had been watching together. He'd missed the last thirty minutes, at least.

"Good morning," she teased him, snaking her arm around his waist and leaning in for a kiss.

"Sorry," he said sheepishly, "Did I miss anything important?"

"Rosebud was the sled." He loved it when she sassed him.

"Funny." He couldn't resist pulling her close and then poking her in the ribs. She responded to that by twining both arms around his neck, kissing him again. Deeply. Purposefully. Wow. This was clearly turning into a major makeout session; and even after six months together, he still felt like he could never get enough skin contact with her. He couldn't help smiling a little at the feel of her under his hands. The texture of her skin still got his heart to pounding, as his hands chased up and down her back, glorying in the satiny touch.

She leaned back, then, arching her neck as she shucked off the t-shirt she'd changed into after work, throwing it unceremoniously onto the floor. Mark felt his mouth go dry at the sight of her. She was hot; holy shit. He must be the luckiest guy on Earth. With a girlfriend sixteen years too young for him.

He pulled back, abruptly. What the hell was he doing, here? Self-doubt was creeping in, as he tried to picture a future for them, together. In twenty years, Sophia would still be young and beautiful and vital, and he'd be... Oh, God. What if this had been a huge mistake?

"Mark?" She had gently placed one hand on the side of his face. "Where'd you go, just then?"

Her eyes were locked on his, with that soft, sweet, smile that he loved. She brushed her thumb across his mouth and then kissed him again, softly. Testing him. Checking to make sure he was still into this; into her.

He found that indeed, he was.