Scientists have long known that pain’s intensity is difficult to measure because people experience pain differently. In the case of 17-year-old Sarah Taylor, doctors struggled to understand her levels of pain from childhood arthritis and fibromyalgia. “It’s really hard when people can’t see how much pain you’re in, because they have to take your word on it and sometimes, they don’t quite believe you,” she said. Some scientists working with Taylor are now trying to develop an objective way to measure pain. They are measuring the reaction inside Taylor’s eyes when she reports pain and when she does not. Dr. Julia Finkel is with Children’s National Medical Center in Washington. She invented an experimental device that is being used with Taylor.