Warning: This is one of those "I won't pretend it makes any sense" stories.
Standard disclaimer here.

Tenten knows that she sees things in a slightly skewed way. She knows that the world is vague and fuzzy in her eyes, and that blackness eats away at the edges. She knows that the world is flat, and that if she stepped off the side it would be a long, long fall before she hit anything strong enough to break her momentum.

It's her reality, and she doesn't like it or love it, but she can live with it so it's just fine.

She sees shadows where others see sunlight, black where others see blue. It's the way things have been for almost as long as she can remember, and she doesn't mind it so much—it is her 'normal'.

Sometimes she has relapses, and everything grows dim and hazy. That is to say, even dimmer and hazier than they were before. She can't recall what the world looks like bathed in sunshine, but the thought leaves a bitter taste in her mouth so she doesn't think about it all that often. Her world is tilted on its axis, and the oceans run into puddles on her floor. She's at a huge disadvantage as a shinobi, and the blackness in her mind promises that her career will be a remarkably short one. Nevertheless, she's determined to carve out a niche for herself before she goes.

Never has she told anyone about her vulnerability, but she thinks that some of them have guessed. Tsunade-hime has access to all her old medical files, and so it is no surprise when she feels the concerned gaze on her back. Her teacher pushes her just like a teacher should, but not as hard as either of the boys—as if he's afraid that she will break. Lee is so naïve, she doesn't want to have to tell him. He sees her as an older sister, and a strong female influence that will help him understand the ways of girls. No serious opponent, no serious threat. Neji probably knows already, considering he is the most observant person she's ever known. Not to mention the fact that he's her closest friend, if she could be so bold as to suggest it. He doesn't treat her any differently, and for that she is more than grateful.

"Tenten." The Hyuuga prodigy's voice is quiet, but blunt, having no question whatsoever in the tone. "You're distracted. Tell me why."

Most other people might have been offended by the lack of concern in his voice, but she knew better—he wouldn't have mentioned it at all if he wasn't worried. He doesn't have to ask, he orders. After all, he is the Hyuuga Neji, genius of his clan. "It's nothing. Really," she adds after seeing his disbelieving look. Tenten smiles slightly in reassurance, and says apologetically, "I'm sorry, I just have a lot on my mind."

He nods, and lets the matter drop.

Two days later and her condition is steadily getting worse. The Hokage requests a brief meeting with her, and the older woman looks somber when Tenten arrives.

"Hokage-sama, you wished to speak with me?" she asks curiously, bowing with respect and taking a seat opposite her idol. She thinks she knows what this is about, but tries not to let her apprehension show.

Tsunade looks at her with an unreadable expression. "Yes, I did. Tenten, I've spoken with your sensei, and… he has told me that you've been growing increasingly distracted during training sessions. Your teammates have noticed it too. I think, considering your condition, that perhaps you should consider an early retirement."

Her dark brown eyes grow very wide, and her jaw drops in horror. "No, please! Hokage-sama, I'm fine, really! I've just been thinking a lot about… other things, and have been a bit preoccupied, that's all!"

"So," Tsunade says gently, suddenly looking at her in a surprisingly maternal way, "This doesn't have anything to do with your being blind?"

Tenten winces sharply, and says in a weak voice, "No… I'm not blind, I just…"

The older woman purses her lips slightly, and nodding. "I see. Visually impaired is the term you're going with, then? You are dismissed, Tenten. Please consider what I've said."

She bobs her head in assent, but the suggestions leave her mind as soon as she leaps from the window.

It has been a week now since she spoke to the Godaime, and she has just completed her most recent mission. It had gone badly, one of her occasional relapses occurring inconveniently soon after they were ambushed by a group of enemy shinobi. They being she and Neji—Lee had gone on ahead to protect their target from the ninja that were currently attacking them.

They had been taken by surprise, but not entirely off guard. Neji had seen them coming for a long distance, but had been unable to judge how many there were, considering they were so closely huddled together that it appeared as if they were one single, shadowy entity. He had taken out a few of them immediately, and Tenten had killed a good number of her own as her bladed weapons danced through the air. It hadn't been so bad, until Tenten's vision suddenly went blurry and everything faded to a deepest hue of black. "Shit!" she had hissed, swaying slightly, quite abruptly betrayed by her own eyes. She had done her best to fight blindly, but all she had to go by were the vague charka patterns she could sense, and it was proving to not be very much help to her. In the end, Neji had taken out all of their foes, but she had been wounded rather badly in her right thigh, and one of her Achilles tendons was slashed rather viciously and was now bleeding profusely. Her teammate was little more than tired, but she wasn't even able to walk on both of her injured legs. There isn't any hospital in this village, and so he takes her back to their room at the inn so he can bandage her up himself.

"What happened?" he demands, sounding extremely cross.

Her eyesight hasn't gotten all that much better, and his image continuously swims in and out of focus, "It's… nothing. I was distracted. It won't happen again," she whispers, surprising him with how uncharacteristically vulnerable she looks.

She knows he is angry when he brings his face closer to hers, glaring hard. "It wasn't 'nothing', and if you don't tell me what is wrong with you, I'll personally make sure that there isn't any opportunity for it to happen again. I'll have you suspended," he snaps, and Tenten blinks back tears.

"I…" she murmurs quietly, burying her face in her hands, "I'm…"

"You're what?" Neji demands, squeezing her arm painfully.

He hears the words, going blind, and the world stops.

It isn't something we can cure… or treat, for that matter.

I am very sorry, Kuroyuri-san, but there isn't much hope of recovery for your daughter. She may never be able to see properly again.

Your daughter has a serious medical problem, like nothing we've ever seen before.

We're not sure what causes it, so there is no way we can hope to cure it.

Ssh… Ten-chan, everything will be okay.

Hush, sweet child. Mommy is here. Can you see me, Ten-chan?

Is there anything you can…? No? I… Yes, thank you doctor. I'll talk to her…

Sweetheart, there is a procedure…

It's risky.

Mommy can't tell you what it does, honey, but will you try?

Ssh… Love, don't cry.

Mommy loves you. Mommy will always love you.

Can you see me?

Tenten.

Tenten?

Tenten!

TENTEN!

There was a picture on her nightstand, of a pretty brown-eyed woman embracing her daughter tenderly. Tenten smiles sadly, trailing her fingers over the glass, a wistful sigh building up in her chest. "Mother…" she whispers, and remembers.

Her mother had left behind two things in the world: her daughter, and the only thing of hers that Tenten had.

Her eyes.