Specifically designed preservative-free formula provides instant and long lasting relief of dry and tired eyes. Optrex Double Action Dry Eye Drops works with your eyes to help restore their moisture. Pr s instant relief as required. It contains two times more hydrating ingredients compared to current Optrex base dry drops. These polymers form a mesh like network on the ocular surface to help stabilise the tear film therefore helping to rebalance the natural moisture of the eye.