Contact lenses have their own care solution and it is not recommended to put them in pure water. Although it is pure water, there are usually bacteria or other protein substances in the water. If there are protein substances, they can easily adhere to the lenses and cause a decrease in the life of the lenses. If there are bacteria, there is an even greater danger that the bacteria will attach to the surface of the lens and then be worn on the human eye, causing a bacterial infection in the cornea or conjunctiva of the human eye. If there is damage to the cornea, it may cause a deeper infection in the cornea. This deeper infection, if it heals and forms a scar, can easily affect vision. Contact lenses must be worn strictly aseptically so as to prevent infection and reduce its side effects.