ContactLensContact lens wearers are familiar with the phenomenon of the wandering lens. What should you do if you can’t visualize the contact lens of a patient, who presents with a “lost contact lens” in the eye? You have the patient look in all directions and you evert the eyelid, but still no contact lens can be found. The patient swears that it’s there because of the painful foreign-body sensation.

Trick of the Trade: Fluorescein dye

Fluorescein Strip Eye

This trick was written by Dr. Ciro Paolillo from the Italian EM website MedEmIt by Dr. Gemma Morabito et al. No, I don’t read Italian but my browser, Google Chrome can! The browser automatically recognizes that the text is not in English and asks me if I want it translated. While the translation isn’t perfect, I can definitely understand the gist. The following is a summary.

Apply a drop of fluorescein dye in the eye. The contact lens will absorb the dye and appear yellow. This serves as a reminder that you should check to be sure that patients have removed their contact lens before instilling fluorescein. It permanently stains the lens.




Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at Bio:
Michelle Lin, MD