OPTASE® Allergy containing Ectoin is a safe, effective, convenient, and ease of use, treatment option for allergic conjunctivitis. Ectoin is a naturally occurring molecule produced by micro-organisms that flourish in harsh and dry environments such as salt lakes and deserts. Ectoin has been shown to be well tolerated and safe, with the ability to increase hydration and stabilize the lipid layer of the tear film as well as reducing inflammation. Preservative free they can be used from 1+ year and are suitable for use with contact lenses. Ingredients : Ectoin (2%), Hydroxyethyl Cellulose, Sodium Chloride,Water, Citrate Buffer Pack contains 20 single dose units with a shelf life of 30 months.