Comprehensive Ophthalmology, Cornea/External Disease, Neuro-Ophthalmology/Orbit
Fluorescein dye should be used to detect defects of the corneal epithelium, as seen in abrasions. Here a drop of sterile fluorescein dye strip is being applied to the lower fornix. With blinking, the fluorescein spreads over the cornea. The dye adheres only to defects in the corneal epithelium defect, and defects in the epithelium light up bright yellow-green under cobalt blue light.