Human vision faces numerous dangers during the months of summer – swimming and bathing in ponds and public swimming pools pose the greatest risks. Almost 90 percent of stagnant water in the Czech Republic is regularly infested with cyanobacteria. Swimming and bathing in such water infested with cyanobacteria can cause conjunctivitis or corneal inflammation, and the treatment of such inflammation is sometimes complicated and can cause permanent eye damage. The cyanobacteria are particularly dangerous for young children, the elderly, pregnant women, allergy sufferers and contact lens wearers.

When analyzing water from public swimming pools, the occurrence of human urine is no exception. Eye protection with swimming goggles is suitable in any water. In every type of water, there may be some danger – most often the effects are irritated and red eyes, conjunctivitis, and in severe cases also corneal inflammation.

It is generally recommended that you look for an officially operated pools or water where the water quality is regularly monitored and checked, and to follow a few important rules. Firstly, it is important to choose good-quality and well-fitting swimming goggles that protect your eyes from dirt and bacteria. In the ideal case, you should remove the contacts before swimming. If a person wants to swim with contact lenses, the combination of swimming goggles and such contact lenses is recommended which you can throw away right after having a nice swim. It is also important to remember not to rub your eyes when in the water.

Even swimming in the sea is not without a risk. It is especially by the sea where people often like to look underwater and watch the underwater life. But what they shouldn’t do is to do this without diving goggles. Opening your eyes under the water without protective goggles for a short time does not hurt provided the water is clean and the swimmer´s eyes are healthy. A longer contact of your eyes with the water may be irritating to the eyes and problems may occur. In the case of easily irritated, allergic eyes, or eyes with any other ophthalmic disease, opening them without an appropriate eyewear is not recommended at all.

Even after bathing it is good to pay some attention to your eyes. This will prevent possible subsequent complications. A foreign body, such as fine sand, may get into the eye while you are swimming. For this reason, it is important to keep in mind that you should not rub your eyes after swimming  as even a tiny grain of sand can scratch the eye unpleasantly. The hypersensitivity of the eyes to chlorinated water is no exception. Therefore it is good to rinse your eyes with clean water, or to use some artificial tears to wash your eyes with, remove any dirt and soothe them.