Used primarily in ophthalmic formulations to treat allergic conjunctivitis. It acts as a mast cell stabilizer and histamine H1 receptor antagonist, helping to reduce itching, redness, and swelling of the eyes caused by allergic reactions. Commonly prescribed as eye drops, it provides rapid relief and is suitable for both seasonal and perennial allergic eye conditions. Its dual mechanism of action makes it effective in preventing and managing early and late-phase allergic responses. Well-tolerated with minimal side effects, it is often recommended for long-term use in sensitive patients, including those with contact lens wear or mild ocular surface disease.