I could suggest a half face mask (no more than 20-25€), combined with some cheap swim goggles (less than 5€).
Just to note that different chemicals can be used in different places, or in different times so not too sure if this will work where you live. For this reason, I would strongly suggest talking to people that currently attend protests or even better are on a med team, because they can suggest specific antidotes for the tear gas used and have the antidote with you (for you or anyone else). I say this because often people say stuff like wash your eyes with water but depending on the chemicals used, this could make the burning pain worst.
I don't agree with this article, but I really appreciate the work of one historian mentioned at the end in the Reference section.
Fernand Braudel decided to take a look at history from a different point of view, especially in relation to time. Instead of talking about specific dates of big events and big names, he decided to look at the conditions of everyday life of common people (food, shelter, human interactions, work etc) who lived around the time that these big events happened, and draw conclusions taking these factors into consideration.
For example one of his takes on why capitalism was created in Europe and not Asia or the Americas, is related to dietary habits, cultivation and transportation methods of wheat, rice and corn respectively.
I'm not too sure of the english title of the book I'm talking about, cause I read it in french and the title was very different to the ones I find in english (La dynamique du capitalism).