A previous post regarding Sublime Text 3 and High DPI screens on a Linux system was nothing more than a bad workaround, if that. Fed up with a bad looking situation, I decided to delve deeper into things. Mentions were there of changing the value of text-scaling-factor using gconf-editor, gsettings or dconf-editor, but doing so made absolutely no difference for my Sublime. In the end, I stumbled upon a simple Sublime setting.

Indeed, a setting, so you can just go ahead and open your user preferences (Preferences → Settings - User). Next, add the following line: "dpi_scale": 2.0. If you have not yet changed settings here before, the file has to follow the JSON format, so be sure to place the appropriate commas. After adding the line, save the file.

With the setting changed and saved, just restart Sublime Text. Everything should finally be readable again, without a need for nasty workarounds.