Soft contact lenses are the ideal vision correction choice for many patients because soft contact lenses allow patients to have better and less restricted vision, they allow for an increased ability to perform work tasks and play sports, and they provide patients with a better perceived cosmetic appearance compared to spectacle lenses. While millions of people worldwide benefit from contact lenses, many of these patients experience contact lens discomfort, which limits their wear time and in many instances eventually result in discontinuation of contact lens use. In fact, 21% to 64% of contact lens wearers permanently discontinue contact lens use because of ocular discomfort. Contact lens discomfort is currently defined as "a condition characterized by episodic or persistent adverse ocular sensations related to lens wear, either with or without visual disturbance, resulting from reduced compatibility between the contact lens and the ocular environment, which can lead to decreased wearing time and discontinuation of contact lens wear." Although contact lens discomfort may stem from the lens itself, a situation that can be corrected by such means as switching to an alternative material or wear schedule, contact lens discomfort more typically occurs from ocular surface disease.

A common first line treatment for patients with dryness symptoms or contact lens discomfort is the application of artificial tears or rewetting drops, respectively. Rewetting drops are specifically formulated for use with contact lenses while artificial tears are indicated for dry eye. Modern rewetting drops and artificial tears have similar formulations with similar preservatives, preservatives that have been shown to be compatible with contact lens use. While rewetting drops and artificial tears are regulated under different U.S. Food \& Drug Administration policies, artificial tears are not specifically indicated for use with contact lenses. Nevertheless, clinicians commonly prescribe artificial tears to contact lens wearers likely because newer formulations of artificial tear have the potential to outperform available rewetting drops (e.g., some artificial tears have lipid supplements that have the potential to restore the external tear lipid layer). The safe and effective use of artificial tears with contact lenses is supported by Caffery and Josephson and Ozkan and Papas who found that artificial tears significantly reduce dryness symptoms in contact lens wearers. However, the community currently lacks a rigorous scientific study aimed at understanding the utility of lipid-containing artificial tear (or rewetting drop) for alleviating contact lens discomfort while patients are wearing their contact lenses. Systane Complete, a new formulation of artificial tears, combines elements from both Systane Ultra (indicated for aqueous deficient dry eye) and Systane Balance (lipid-containing artificial tear indicated for evaporative dry eye). Thus, the purpose of this study is to test the safety of Systane Complete and its ability to alleviate contact lens discomfort during the day while subjects are wearing their contact lenses. This goal will be accomplished by randomizing subjects to either Systane Complete, a commercially available rewetting drop, or no treatment.