Opticrom Hayfever 2% w/v Eye Drops Opticrom Hayfever 2% w/v Eye Drops relieve the symptoms of seasonal allergic conjunctivitis, often known as hayfever eyes. They contain an active ingredient called sodium cromoglicate, an anti-allergic medicine that works by stopping the release of the natural substances in your eyes that can lead to an allergic reaction. Opticrom Hayfever 2% w/v Eye Drops are only suitable for eye irritation caused by hayfever. You can be sure allergic eyes are caused by hayfever if: Both eyes are affected. You also have a runny or blocked nose. Your eyesight is not affected. You know you suffer from hayfever & your symptoms coincide with the times of year when grass or tree pollen is high.