Rose Bengal is a red or rose color dye and is anionic in nature. It.is widely used to detect damage to the ocular surface epithelium in ocular surface diseases such as dry eye and herpetic keratitis
Rose bengal free acid is a xanthene dye that is fluorescein bearing bromine substituents at positions 2', 4', 5' and 7' (on the xanthene ring) and iodine substituents at position 2, 3, 4, and 5 (on the phenyl ring).The dipotassium salt is the biological stain 'rose bengal'. It has a role as a fluorochrome.