For brain surgeons, the shift is the sticking point. When a surgeon opens the cranium to remove a tumor, the brain moves as much as 1 cm, making much of the pre-operative mapping of the tumor essentially useless. While the bulk of a lesion can be identified by its density, the tendrils blend into the surrounding tissue – and taking excess margins means more brain damage. Designs for Vision Inc.’s bright idea, a headlamp that illuminates a fluorescing tumor with a laser light, makes brain surgery quicker, safer and more accurate.