CROMAL ForteCromolynCipla Pharmaceuticals Ltd. Rx quality 4 x 5mL Eye Drops 4% w/v . This medication is used to treat certain allergic eye conditions (vernal keratoconjunctivitis, vernal conjunctivitis, vernal keratitis). It prevents itching of the eyes that can occur with these conditions. Cromolyn is known as a mast cell stabilizer. It works by blocking certain natural substances (histamine, SRS-A) that cause allergic symptoms.How to use Cromolyn OphtRead the Patient Information Leaflet provided by your pharmacist before you start using cromolyn and each time you get a refill. .