I work in a bit of construction, building and renovations. I've gone through several health and safety training over the years. Some of it has to do with protecting yourself from sharp objects and flying debris. There is quite a bit of training in protecting your eyes, especially when you are around metal saws, wood saws and anything to do with cutting machinery. You don't want small particles or objects flying into your face, especially onto your eye.
Which is why there are so many stringent regulations on eye protection and the technology is so far advanced now that you can wear eye protection that can protect your eye from flying debris or objects like a nail gun fired right at your eye.
Nail gun on safety glasses test
A broken angle grinder blade can travel at extremely high speeds, potentially reaching 120 m/s (430 kmph) or even higher. That's basically a small piece of hardened material flying like a knife through the air that can slice through your skin, into your bone or puncture your eye and blind you.
Worker's angle grinder blade snaps and gets stuck in safety glasses
If you are wondering which safety glasses to get ... buy them at a hardware store. They are more likely to carry actual safety glasses. Department stores or discount stores sell 'safety glasses' but they are usually not industry rated and are only meant to protect against dust and liquids - they will not protect you against high velocity impact.
Look for safety glasses with anything marked ANSI Z87+, sometimes written Z87.1+ (note the plus) rated or CSA Z94.3 rated are ensured to safely withstand a direct high energy strike. These glasses are meant to supply workers everywhere so you can buy these for about $10 to $30 depending style and type. Buy them in bulk and they're much cheaper overall (just make sure they well marked and approved). Well worth the money to save your eyes.
After all this work, effort and technological development to get to the point where there can be political protests on the street and police and security forces can fire small projectiles at people and put their faces and eyes in danger. Small pellets, bean bags or tear gas canisters can give you a bruise or even cut you if they hit your back, legs, arms or chest. But these things can potentially blind people if they are hit in the face. Police are told not to aim them at people's faces but in a chaotic situation where people on all sides are angry, anxious, tired and afraid, anything can happen. In some parts of the world, police and security forces are directed to purposefully aim at people's heads and faces.
Safety glasses will protect you from these low velocity munitions from police. If they are firing things at people that are faster and stronger than this, then they are using lethal force and basically shooting at people with shotguns. If your glasses can stop flying objects, then they are firing non-lethal or less-lethal rounds .... anything stronger or faster than that and no safety glasses can protect you and your whole body and not just your eyes are in danger. Basically, if an object can be fired through a pair of industry rated safety glasses ... the same object can blast through your skull.
In the workplace, I can't walk into a potentially dangerous situation without wearing safety glasses .... but at a public protest where police are firing things without much control? No one is told of the danger and in some jurisdictions people are discouraged or punished for trying to wear any kind of safety gear. Even in first world countries like the US, Germany, France and Canada, people wearing safety glasses at a protest are targeted as terrorists, criminals, instigators, or potential violent criminals.
I really don't care what anyone has to say on the matter whether for legal, moral, ethical, political or security reasons ... if you are joining a major protest anywhere in the world from now on ... wear safety glasses ... approved, industry rated safety glasses. They are easy to find and not that expensive and they can be found in most hardware stores or ordered online. They are made freely and easily available to protect workers in just about every industry, so there is no excuse for young people joining in a major protest to not wear them.
One of the saddest stories I ever saw was the story of 20 year old Gustavo Gatica in 2019 who was part of a protest against the government in Chile. Police were actively shooting at protesters' faces on purpose blinding many people in one eye. Gustavo was hit in both eyes and was rendered completely blind.
https://www.amnestyusa.org/gustavo-gatica/
It's one of the saddest and most infuriating images I've seen in a long time ... no matter where you are and you want to join a protest ... wear safety glasses and save your eyes. Police might not try to aim for your face but if they do, they'll just make the excuse that you shouldn't have been there in the first place and blame you for your injuries.
To me the distinction is striking ... if we are working for corporations and government, they will protect and defend the right to our safety to the utmost degree ... but if we disagree or protest against government and corporations, then our safety no longer matters and is instead endangered.
Wear your safety glasses
I have a couple of friends who do the exact same thing .... but it isn't funny or humorous