Sodium cromoglicate 2% eye drops. Catacrom is a preservative free eye drop for the prevention and treatment of allergy symptoms. Catacrom eye drops is used for the relief and treatment of allergic red, watery, itchy and puffy eyes caused by hayfever, house mites, and other causes of allergy such as pet hairs. Eye allergy can happen when sensitive eyes are exposed to these causes of allergy. These eye drops can be used by wearers of rigid or gas permeable contact lenses and can be used by people who are sensitive to preservatives in other kinds of eye drops.