The goal of this research is to evaluate and compare the effectiveness of Systane® versus Optive™ on aqueous tear film stability in patients with a diagnosis of Dry Eye Syndrome and to determine the possible application for this product in the future. Systane® is marketed as over-the-counter tear lubricating therapy in the United States under the FDA monograph.

Twenty (20) patients will be enrolled in this two-period crossover, randomized study design. During the course of the study, each patient will be treated with each test article in the clinic at separate visits. Following the informed consent procedure, a general ocular evaluation, including corneal and conjunctival staining and Schirmer testing, will be done and evaporometry assessments will be completed to determine baseline tear evaporation rate. This will occur before any test article is administered to the patient.

Qualified patients will be randomized into two treatment groups. After 1 hour, in order to eliminate any residual sodium fluorescein, patients will be administered one drop of Systane® (40 µl) or Optive™ (40 µl) in each eye per randomization assignment. At 30 minutes following instillation of the drop, the evaporometry measurement will be repeated. These evaporometry tests (pre and post instillation of drops) will be performed in order to establish a comparison for later analysis. The estimated time in completing each study visit will be 180 minutes per visit. Patients will be asked to return to the clinic after 2 - 14 days for evaluation of the 2nd assigned crossover treatment (i.e. patients who initially received Optive will receive Systane and patients who initially received Systane will receive Optane).

During the interim study periods, patients will be asked to continue their pre-study routine; using their pre-study ocular lubricant or other tear products at the same frequency. Any changes in the frequency of product use during the interim period or any changes in other concomitant medications will be carefully recorded. This is especially important since many prescription products (e.g., Claritan) have significant effects on lacrimal gland physiology.

An effort will be made to schedule all study visits at approximately the same time of day in order to reduce diurnal variability. For the similar reasons, all patients will be asked not to use any lubricants or ocular medications for at least one hour prior to their office visits.

Inclusion Criteria:

• Individuals aged 18 and up will be included, where any age over 89 will be recorded as 'greater than 89.'
• Individuals with bilateral eye sight eye correctable to 20/80 or better.
• Individuals in good health with or without Meibomian Gland Dystrophy (MGD) but with Aqueous Tear Deficiency (ATD) with minimal to no ocular surface inflammation on slit lamp examination.

Exclusion Criteria:

• Individuals with only one sighted eye or vision not correctable to 20/80 or better in both eyes.
• Individuals with history of punctal plugs or punctal occlusions.
• Individuals with history of keratorefractive as well as ophthalmic disease such as corneal dystrophies, glaucoma, or systemic disease affecting the eye (such as Herpes Zoster).
• Individuals with history of systemic or ocular auto-immune conditions.
• Individuals with active systemic disease or those taking systemic medication that are known to influence AT production will not be considered for this trial.
• Individuals using topical medication who are unable to discontinue them for at least 24 hours prior to baseline evaluation will be excluded as well.

Adverse events were collected for each participant for up to 2 weeks, from time of enrollment to completion of study visits,