If you want to get free glasses, you'd better search online. According to my experiences, online optical shop are more likely to offer free reading glasses when they promote their products. Searching free reading glasses in Google, we can see that Firmoo.com and coastal.com signs of free glasses. You can go their sites and pick up one. Good luck.
i google free glasses, and this site is at number place https://www.firmoo.com/free-glasses.html. I am not quite familiar with this site, you can browse though the page. They are offering free glasses, eyeglasses, sunglasses including reading glasses. Good luck!