This is a pretty quick write, so hopefully it's not too bad. But I've always imagined that maybe Clark's glasses came about something like... this.
"Jonathan!" Martha screamed.
Jonathan immediately dropped the bag of fertilizer he'd been carrying to the fields. His wife's shout sounded desperate, frightened. He took off at a run in her direction.
What he saw made him stop in his tracks. Clark was sitting on the ground, shaking uncontrollably, his hands pressed firmly over his eyes. Martha crouched behind him, her hands firmly on his shoulders. And about twenty feet in front of them was... a bale of hay. In flame.
He detoured towards the trough, and in one swift moment he had filled the pail that was usually used for feeding the pigs. Then he ran towards the bale of hay.
"Jonathan, no!" Martha cried as he stepped in front of it and dumped the bucket of water over the fire, putting it out entirely.
Jonathan turned towards her, startled, just in time to feel a surge of heat soar over his shoulder. The bale of hay caught fire again... despite being rather damp.
"What the--"
"Get out of the way," she shouted, motioning to the left. Puzzled, he moved over to the left, then approached them cautiously. The ground under the bale of hay was dirt, so he wasn't worried that the fire would spread if left momentarily unattended. What he was worried about was Martha's strange reaction.
"Don't walk in front of Clark," she said. "Circle around from behind."
He obeyed, curious. When he was standing safely behind Clark, he asked his wife, "All right, are you going to tell me what's going on?"
"Clark's eyes. He seems to be having some sort of... reaction."
"Reaction?"
"This, Dad," Clark said. Still facing the bale, he lifted his hands from his eyes. A new section of the hay caught fire. He immediately covered his eyes again. "My eyes... they're making it catch fire, somehow. And I can't turn it off!"
Jonathan thought quickly. Then he pulled off his own glasses and dropped them onto Clark's face. Clark removed his hands as he felt the glasses.
"What are you doing?" he asked, turning to his father.
Martha and Jonathan gasped and jumped out of the way, but nothing happened. No more fire.
"Hey!" Clark exclaimed. "It works!"
Martha looked puzzled. "Why isn't the glass just melting?" she asked Jonathan. "It isn't, is it?"
"I think it's because my glasses are such a strong prescription, and Clark's vision is so good. If anything, the glasses distort his vision. Maybe they're keeping it from focusing."
Clark touched the edges of the glasses, which were too big and were slipping down his nose.
"Clark, don't you dare take those off until you learn to turn that vision off," she said. "Sorry, Jonathan, you're going to have to be blind for a while, at least until we get Clark his own pair."
"You know," he said thoughtfully, "even once Clark gets his fire--whatever you call it--under control, it might be good for him to keep the glasses."
"Why?" Clark wailed. "They make me look like a dork!"
Martha chuckled. "I think you look adorable."
"You're my mother," he said darkly. "You have to say that."
Jonathan continued, "Well, nobody would suspect that a boy who has to wear glasses all the time can see everything for miles, including through solid objects. They make him seem a little less... perfect. And," he said to his son, "maybe they'll help you remember to keep your powers in check."
Clark rolled his eyes. "It was one mistake. I don't see why you have to keep bringing it up."
"Because you can't make mistakes, Clark!" Martha said. "If Lana tells somebody else, and they tell somebody else... eventually the whole town knows. And then everybody will be watching you. Once they do, your secret will be history."
He sighed. "All right, I'll right. I'll wear glasses. But can I at least get cool ones?"
"Red with blue stripes if you want," Martha promised.
* * * * * *
Clark stared at his reflection in the mirror. The reflection that stared back at him was startlingly different from the one he was used to. The spandex made an incredible difference. He looked nothing like the Clark Kent who put on a business suit each day and went to work at the Daily Planet. Instead, he looked like... a superhero. A man who wore a suit with a very different purpose. But there was still something Clark-like about his reflection, despite the bold costume.
After a moment, he lifted his glasses from his face, still looking into the full-length mirror. It was symbolic, in a way. He'd worn the glasses since his powers had first begun to appear as a boy. They'd represented the powers he had to keep hidden, to control constantly so that nobody would ever notice anything different about him. Without them... he felt a freedom he hadn't noticed he was missing.
He threw back his shoulders and stood a little taller than Clark Kent ever did. Stood with his feet a little further apart, his arms crossed.
A superhero.