Study of the Effect of Diquafosol Tetrasodium Ophthalmic Solution, 2% Versus Placebo in Dry Eye Subjects (P08634)

Inclusion Criteria: * Provide written informed consent prior to any study procedures being performed. * Have a best corrected visual acuity (BCVAof +0.7 or better. * Have a history of dry eye (keratoconjunctivitis sicca) in both eyes * Have ongoing dry eye disease, in the same qualifying eye or both eyes. Exclusion Criteria: * Have previously had LASIK refractive surgery. * Use of topical ophthalmic medications, preps, gels and lid scrubs during study. * Have had penetrating intraocular surgery in the past 90 days. * Have had other ocular surface surgery (e.g., refractive, pterygium) within the past year. * Have a diagnosis of an on-going ocular infection, clinically significant blepharitis, lid margin inflammation, Stevens-Johnson syndrome or pemphigoid. * Any serious ocular systemic disease or uncontrolled medical condition. * Exposure to any investigational drug within 30 days of study start.