Does “shock the pool” mean dumping in a lot of freshwater after the bonded chlorine levels have gone up?
I would advise against higher levels of free chlorine, because a part of the gas will dissolve away into the air to chloramines, which cause the chlorine smell. Better to put enough freshwater in and keep the pH levels right (which also influences the chlorine).
As to the OPs question: Yes, people should shower before they go into the pool, and they shouldn’t pee into the pool; but people being people, some don’t, and some do (respectivly). Esp. kiddies will do the later due to bad bladder control and the belief that “nobody will notice/see”, so if you want cleaner water, go into the adult pool (if there are two seperate ones).
But even if only a few swimmers are around, chlorine reacts with other organic compounds, too, like skin cells and hairs and whatnot, so there will always be bonded chlorine (the part that stings). That’s why they put the chlorine in in the first place - to sanitze by bonding the stuff. If the pool is properly maintained by adding freshwater to keep the level low enough, your eyes shouldn’t burn, however. (And I have experienced that my eyes burn less over the last decades because stricter regulations have lowered the allowed levels.)
If it’s a problem, and you can’t talk to the pool owner/ manager, I’d recommend swimming goggles.