The purpose of this trial is to assess the effectiveness and safety of 2% diquafosol tetrasodium ophthalmic solution versus placebo following 6 weeks of treatment in subjects with mild to moderate dry eye disease.

Inclusion Criteria:

• best corrected visual acuity in both eyes of at least +0.7
• six-month documented history of dry eye disease
• as least mild severity in 1 of the 5 dry eye symptoms
• corneal fluorescein staining of greater than or equal to 3 and less than or equal to 6 (out of 15)

Exclusion Criteria:

• permanent conjunctival goblet cell loss or scarring conditions
• ongoing contact lens wear
• current topical ophthalmic medication use