Diquafosol tetrasodium is primarily used in ophthalmology as a therapeutic agent for treating dry eye disease. It functions as a P2Y2 receptor agonist, stimulating the production of mucin and fluid secretion in the eyes. This helps to restore the natural tear film, improving lubrication and reducing symptoms such as dryness, irritation, and discomfort. It is often prescribed for patients who do not respond adequately to traditional artificial tear solutions. Additionally, its mechanism of action makes it beneficial for addressing underlying causes of dry eye, particularly in cases related to reduced tear production or poor tear film stability.