Vital stains like sodium fluorescein, lissamine green, and rose bengal are commonly used in ophthalmic practice. Sodium fluorescein specifically is a water-soluble yellow dye that appears green under cobalt blue light and is used to detect epithelial defects, assess tear film and ocular surface integrity, and evaluate conditions like dry eye. It is typically applied topically as an eye drop and stains any breaks in the corneal epithelium bright green. Sodium fluorescein staining is evaluated using standardized grading scales to determine the clinical significance of any observed staining.