Fluorescein is a bright yellow-green dye commonly used in various scientific and medical applications. It is known for its ability to fluoresce, meaning it emits light when exposed to ultraviolet (UV) light. This property makes it useful in fields like biochemistry, forensics, and ophthalmology, where it helps visualize structures or processes. In medicine, fluorescein is often used in fluorescein angiography, a technique that allows doctors to examine blood flow in the retina. It can also be used to detect corneal abrasions and other eye conditions. Overall, fluorescein is a valuable tool for both research and clinical diagnostics.