Some preservatives in dry eye medicines may act as mild irritants. These preservatives present no problem for most dry eye patients. However, ocular irritation can occur in some patients with especially sensitive eyes. Thankfully, there's SYSTANE® Preservative Free Lubricant Eye Drops. Offering the same long-lasting moisture and protection as the original SYSTANE®, SYSTANE® Preservative Free single-use vials are the ideal dry eye medicine for patients with sensitive eyes.