T Walradt, D Svarca. Gastroenterology 2025; 168: 1046-1048. Shining a New Light on
Gastrointestinal Endoscopy: Evaluating the Effect of Green Light vs Dim Light on Performance in the Endoscopy Suite

Background: “Unlike diagnostic radiology, GI endoscopy requires the concerted efforts of a proceduralist, anesthesiologist, nurse, and technician. Moreover, several of these individuals are often performing tasks that do not involve looking at a monitor. The advent of laparoscopic surgery presented surgeons with similar lighting challenges. In response to this problem, some operating rooms have been equipped with green lights to achieve high contrast and low glare on monitors while still allowing for the safe and efficient practice of other tasks in the operating room. The choice of green light is based on the fact that the human eye is most sensitive to light with a wavelength around 555 nm, in the green portion of the visible spectrum. This wavelength provides optimal contrast and sharpness under low-light conditions.”

Methods: The authors “conducted a single-center cross-over study comparing image
classification on video monitors and the performance of multiple nonmonitored based physical tasks in the endoscopy suite using green light and dim light.”

Key findings:

• Performance of physical tasks was significantly faster with green light, including endoscopy setup (43.1 vs. 62.1 s), biopsy sample time (35.8 s vs. 80.1 s), and feeding wire (34.3 vs. 99.1 s)
• There was no difference in polyp detection rate under the 2 light conditions. However, color detection of anesthesia medication tapes and endoscopic tools was better with dim light.
• Eye strain score was significantly better with green light compared with dim light (10.3 vs. 4.1)

My take: Use of green light in endoscopy suites is likely beneficial particularly in more technically-demanding procedures. It makes common tasks easier/quicker and with less eye strain.