Optogenetics is a novel technique of delivering genes that encode proteins capable of conveying light sensitivity to neurons, heralding exciting new possibilities for laboratory-based neuroscience research. This fast-developing field is of particular interest because of the potential application for individualised diagnostic and therapeutic clinical approaches. The authors describe what optogenetics is and how it works, explain its significance to neurosurgery and illustrate its relevance by giving examples of recent translational and future clinical applications.