Opticrom Allergy Eye Drops are for the relief and treatment of allergic red, watery, itchy and puffy eyes caused by hayfever, house mites and other particles e.g. pet hairs. Allergic eyes happen when allergens come into contact with sensitive eyes. When this happens, a number of chemicals are released from special cells in the covering of the eye making them itchy, red and watery. The active ingredient, Sodium Cromoglycate, belongs to a class of medicines known as anti-inflammatory / anti-allergy agents