Superman always has whatever superpowers he needs for the situation. That's one of his hidden superpowers. Like ice breath. Or night vision!
Also, the older explanation for why no one notices Clark is simply Superman in glasses? He was so strong his muscles were capable of fucking up his bone structure. He can change the way his face looks and even make himself shorter/taller.
No, really. I'm not making this shit up. I don't have that level of creativity.
But I guess CRUNCH CRACK SNAP CREEEEAAAAKKKK CRICK CRACK isn't quite as sexy as ripping off a pair of glasses and tearing open your shirt. And that's why nobody brings up that superpower anymore.
