It is a common misconception that red eyes and a strong chlorine smell to the water is the result of too much chlorine. Actually, the cause is not enough chlorine! The combined chlorine compound, called a chloramine, is produced when a free chlorine molecule combines with a nitrogen or ammonia molecule. These compounds smell bad, irritate the eyes and skin, and get in the way of free chlorine trying to do its job.
You can super chlorinate, or use Shock It to oxidise, or break apart these compounds.