1. Plural of fluorescein; synthetic organic compounds that fluoresce brightly under ultraviolet or visible light, commonly used in medical diagnostics, research, and industrial applications.
Usage: technical; chemistry/medicine
2. In ophthalmology, fluorescent dyes used to examine the eye and detect corneal abrasions or other surface damage.
Usage: medical

Examples

• The ophthalmologist applied fluoresceins to the patient's eye to check for scratches.
• Fluoresceins are widely used in biological imaging to track cellular activity.
• Researchers use fluoresceins as markers in fluorescence microscopy experiments.
• The bright green fluoresceins glowed under the ultraviolet lamp.
• Fluoresceins help doctors diagnose corneal injuries quickly and accurately.