Emedastine is primarily used as an antihistamine in the treatment of allergic conjunctivitis. It works by blocking histamine H1 receptors, which helps reduce symptoms such as itching, redness, and swelling of the eyes. The medication is typically administered in the form of eye drops, providing quick relief from discomfort caused by allergic reactions. Emedastine is favored for its rapid onset of action and its ability to provide long-lasting relief with minimal side effects. It is particularly effective for managing seasonal allergies and other forms of allergic eye conditions, improving the quality of life for individuals affected by these issues.