1. They aren't focused on their appearance, or on attracting guys who are focused on appearance. They of course also go easy on makeup
When someone wears glasses these days it's a conscious decision not to use contacts. They feel the hassle of contacts isn't worth it.
2. Since they don't have a lot of Don Trump types chasing them, they have time to chat and talk and have coffee. They don't resent that you arenn't spending money on them. These girls don't rate guys by their cars or bank accounts nearly as much as most US women.
3. Without such a busy social calendar, they are usually well read and can talk INTELLIGENTLY about the world. I rarely meet US girls who can handle any kind of political discussion.UNLESS they are wearing glasses.
4. Quite often the girl in glasses is very attractive, but the glasses mean you don't notice that right away. Since such girls nearly always dress modestly, you are comfortable and not distracted (as a guy) when you first meet them. And the girl is also more comfortable, because she knows you aren't focusing on her looks. She knows she is being taken seriously, and that I might not be true if she were wearing contacts.
5. It's easier to be respectful toward her, as a guy; You don't resort to stereotypes when you describe her, either to yourself or to others. You don't classify girls in glasses by hair color, for example, quite as readily as we guys normally do.
I've heard there are some girls who wear glasses even though their vision is perfect, although I have never met one, just for the reasons above!