Contact lens solution is a highly specialised chemical composition that is ideally suited to the contact lens itself. If you run out of contact lens solution, you should replace it immediately. The best possible thing is to get more contact lens solution, and not try to substitute other fluids for it. However, if you absolutely cannot get more contact lens solution, you can try the following technique.
Contact Lens Solution Types
Most people use multipurpose solution for their contact lenses. There are other contact solution types available, saline solution being one, though it is not usually recommended to use saline alone. In addition, there are solutions that are made for specific lenses, such as soft, rigid gas permeable or extended wear.
Contact Solution Components
Contact lens solution tends to consist of several ingredients, some of which are commonly found in people's homes. Others are more difficult to obtain. The basis of many contact solutions is hydrogen peroxide. Benzyl alcohol is often also added, to disinfect the contact lenses. Contact solution may also include the less commonly found components edetate disodium, polyaminopropyl biguanide and chlorhexidine gluconate. These ingredients serve as chelating agents, preservatives, and antiseptics, respectively. A chelating agent helps bind the metal ions to prevent water staining. Because of these special ingredients, replicating contact lens solution exactly would be prohibitive for most.
Disinfecting Lenses Without Solution
If you are lacking contact lens solution, you can attempt to make a temporary substitute out of deionised salt and water. The salt needs to be in the proper concentration. A general ratio would be 1 tsp of salt per litre of water used. Boil for at least two minutes and allow to the solution to cool. Cooling completely is an important step in order to prevent discomfort or injury to your eye. If the salt solution is too strong, it could cause your eye to dry out. If you have saline solution, you can use that as well.
Dangers of Contact Solution Substitutes
The reason that contact lens solution is so strongly recommended is that the danger of incorrect saline concentration could cause dry eyes. Furthermore, the saline solution by itself does not disinfect the contacts, which could lead to infection. You can also attempt to rinse the contacts with distilled water by itself, but this could also disrupt the saline balance of your eyes.