For Dr. Sam Achilefu, the director of Washington University School of Medicine's Optical Radiology Lab, the challenge in cancer-removing surgery was clear.

“Surgeons told me that one of their problems is seeing beautiful static images of MRI and CT scans—but then when you go into the operating room you have truly nothing,” he tells “TechKnow” in this week’s episode. “It’s like walking in the dark.”

During surgery, the goal is to take out all of the cancerous tissue—and the rim of tissue around it, known as the surgical margins. After removal, this tissue is examined. If the cancer cells come to the edge of the tissue—or just too close to the tissue—additional surgery may be recommended.

According to the National Institutes of Health, between 20 and 25 percent of all breast cancer patients must undergo additional surgeries, and skin melanomas almost always require at least a secondary surgery to get a wide enough margin.

“The goal is to be able to detect very small cells,” Achilefu says. “And the current imaging systems are not capable of doing that.”

So Achilefu developed infrared goggles that are now in an early experimental phase, being tested for accuracy. And so far, they are confirming earlier tests that detected cancerous cells with high accuracy—and allowing surgeons to more precisely target what additional tissue on the margins needs to be removed.

Here’s how it works: