SCIENCE: CALTECH RESEARCHERS DEVELOP TECHNIQUE TO FOCUS LIGHT INSIDE BIOLOGICAL TISSUE. “While the previous limit for how deep light could be focused was only about one millimeter, the Caltech team is now able to reach two and a half millimeters. And, in principle, their technique could focus light as much as a few inches into tissue. The technique is used much like a flashlight shining on the body’s interior, and may eventually provide researchers and doctors with a host of possible biomedical applications, such as a less invasive way of diagnosing and treating diseases.”