Why Preservative Free? Like so many people these days, you may be taking an active interest in your health - exercising, watching your weight and being more careful about the ingredients in all the products you use. REFRESH eye drops are preservative free and will not cause allergies or adverse reactions associated with eye drop preservatives. People with sensitive eyes and contact lens wearers can confidently use REFRESH eye drops. Why Sterile Single-Use Containers? Eye drops are prone to bacterial contamination and are therefore generally discarded ⁴ weeks from the time of first opening the bottle. REFRESH eye drops are different. Each single-use container remains sterile until it is opened. Therefore there is no need to discard REFRESH eye drops like bottled eye drops. Additionally, the single-use containers of REFRESH eye drops are convenient and easy to carry.