Hylo-Dual preservative free eye drops are for use:On dry eyes cause: by allergies. It also helps to stop itching and burning. Hylo -Dual is the only preservative-Free eye drop with precise dosing specially formulated to combine (0.05%) sodium hyaluronate and (2%) ectoin. The drops create a protective shield from pollen, dust particles, animal hair and other environmental allergens. They can be use: with contact lenses and are suitable for adults and children 6 years and over.