Scientists have a new tool to precisely illuminate the roots of nerve pain. Engineers at MIT have developed soft and implantable fibers that can deliver light to major nerves through the body. When these nerves are genetically manipulated to respond to light, the fibers can send pulses of light to the nerves to inhibit pain. The optical fibers are flexible and stretch with the body. The new fibers are meant as an experimental tool that can be used by scientists to explore the causes and potential treatments for peripheral nerve…