A friend of mine posted this link on his FB page and after reading it I had to comment with the info I have learned from here. Is my comment accurate, if not please let me know?
Red Eyes Caused By Peeing In The Pool
"It's not the pee itself that burns your eyes. A pool with proper chemical levels will not burn your eyes. There are also 2 different types of chlorine that should be tested in a pool. Free Chlorine & Combined Chlorine. A 3rd level that also needs to be monitored is Total Chlorine, TC is the added total parts per million of the FC & CC. FC is the level of chlorine in your pool that should be checked EVERYDAY if you have a manual feed chlorine pool. CC is a byproduct that's created in the process of the FC sanitizing the pool. CC is what causes the "chlorine" smell and can cause your eyes too. A pH that's to low or to high can also cause your eyes to burn. So basically peeing in the pool puts urine in the pool that the FC is trying to clean and that creates CC and that's what is actually burning your eyes. It's not just pee that causes CC to rise, any type of bacterial that's in the pool will cause it to rise. That's why it's important to keep your FC in range and that requires daily adding of liquid chlorine. Why chlorine tablets or granule chlorine shouldn't be used is a whole other topic. I have been studying pool chemistry for about 3 months now and have learned a lot and with what I have learned I would bet my house that at least 90% of privately owned manual chlorinated pools do NOT have correct levels and are NOT safe to swim in."