This is a multi-site, randomized, investigator-masked study to evaluate the physical effects of Systane(R) versus Refresh Tears(R) in subjects with moderate to severe dry eye. It is a 6-week, perspective, randomized, active-controlled, investigator-masked, parallel group study.

Inclusion Criteria:

• Patient must be 18 years of age or older of any sex and any race, with a score of at least 2 (some of the time) on the subject-assessed Symptom Eligibility question.
• A sodium fluorescein corneal staining sum of ≥ 3 in either eye.
• A best-corrected visual acuity of 0.6 logMAR or better in each eye as assessed using an ETDRS chart.

Exclusion Criteria:

• A history or evidence of ocular or intraocular surgery in either eye within the past 6 months.
• Lasik patients can be included if lasik surgery was greater than 6 months prior to the initiation of the study.
• A history of intolerance or hypersensitivity to any component of the study medications.