0.5% saline solution, or 0.9% diluted one part solution, to one part water. Just make sure it is only saline solution you are getting, and it does not have anything added to it.
this is the contents a sterile, isotonic, buffered solution containing the equivalent of 0.9% w/v sodium chloride with boric acid, borax, sodium perborate, phosphoric acid and water - purified
Most readily available saline solution contains ingredients to reduce the impact on the eye (buffering agents) and to prevent contamination by outside germs. These are solutions you would be fine putting in your eye.
Kent67 is right. It's a basic eyewash and so very safe for even delicate things like eyes or chameleons.