I get it, it's the 32nd century and the glasses are maybe heads up displays that only he can see and use. But don't you think in three thousand years they would have figured out how to build that stuff INTO or ONTO the eye? Instead of making the person, or the person choosing to wear an ancient form of corrective lenses.
Glasses are fashion items as well. Even when they've become entirely useless, people will still wear them, just like other non-functional clothing items like ties.
It'd be like a modern day executive wearing cufflinks.
We've had buttons for a long time, some people are just hipsters.
But also, Star Trek has a long history of justifying contemporary-looking people as a fashion choice. I've always remembered this one thing from one of the novels where they imply that they can easily keep everybody thin and fit indefinitely, but admirals like to get a bit pudgy on purpose because it makes them look stately.
And also makes casting and wardrobe choices a lot simpler, but I don't think the book said that.
There are quite a few examples of this actually happening. I've already mentioned neckties, but perhaps a better equivalent would be high-heels. Once worn by men as functional riding shoes, they've now entirely lost that use and are worn by women solely as a fashion item.