Comments:-

Dilutions of EDTA in the region of 0.4% are used in preparations as a chelating agent. As a chelating agent, it is active upon divalent cations and so can help remove calcium carbonate or calcium phosphate deposits from the ocular surface tissue, and is therefore useful for irrigation in ocular emergencies. Lower concentrations are used as a preservative, typically less than 0.1%, and act as a mild bacteriostatic and stabilising agent.