Eye Irritation

"As you are probably aware, eye irritation is something a good majority of people will experience this swimming season.  This is not uncommon because there are several reasons why this happens.  One reason for this problem is having a dirty filter or pool.  If the filter is dirty, it becomes incapable of removing small particulate matter, chloramines, from the water and therefore it gets into the eyes and irritates them.
The most common form of eye irritation is urine in the water.  When urine is present, the reaction is so intense it will burn the eyes.  Urine is basically ammonia.  Ammonia and chlorine do not mix.
 If you do experience eye irritation, we recommend that you backwash and/or clean the filter and let it run continuously for twenty-four hours.  Verify that the pressure in the pump is not too high.  Bear in mind, most gauges are not always accurate.  The best indication of a filter needing to be cleaned is to make sure the suction in the skimmer is as strong as it was when it was backwashed the last time.  If it is weaker, this indicates the filter needs to be cleaned.  If you are not sure of the suction, backwash anyway to confirm you are getting 100% filtration."

I must admit.
When I was complaining to Bally Total Fitness about extensive usage of chlorine in their swimming pool, I was wrong. I was swimming in urine!.