Jason Howland | (TNS) Mayo Clinic News Network For many people, the hot summer days are often spent swimming at the pool. But even though the water is usually clear with chlorine, it doesn’t mean you should be looking underwater. And as a Mayo Clinic eye expert explains, it could cause temporary damage to your vision. The next time you dive in, you might want to reconsider opening your eyes underwater. “Chlorine is a pretty powerful disinfectant and can, in fact, cause some damage to the outer layer cells that protect the cornea,” says Dr.