Giacomo, what font are you using for Applications? Steps to check:
1 - Left-click on desktop
2 - Click on "Change Desktop Background"
3 - Click on "Interface" tab
4 - See font style and size to the right of "Application font:"
Are the menus on all other apps (eg.: Firefox) working fine?
Also I noticed that great part of pdfs aren't fully readable. There are parts of text that are invisible. The only way to read them is to select, copy and paste them in another software.
seems a font configuration issue of a fontconfig bug rather than an evince one there