Aller-Nil Drops 5 ml is used to treat eye redness, itchy and watery eyes caused by allergies such as hay fever, per hair and house dust mites. It contains Sodium cromoglycate, which prevents the release of histamine, a substance responsible for causing allergic reactions. Thus, it prevents allergic response and reduces allergic symptoms. In some cases, you may experience stinging or burning in the eyes, blurred vision and eye irritation. Before using this medicine, you should tell your doctor if you are allergic to any of its components or if you are pregnant/breastfeeding, and about all the medications you are taking and pre-existing medical conditions. If you are using two eye medications, wait for at least 5 to 15 minutes before using the other eye medication.