Optogenetics, pioneered just three years ago for use in neuroscience experiments, is hitting its stride, as increases in venture and grant funding in the space attest. The research technique involves the delivery of genes or chemicals to activate neurons in response to light. The approach holds the potential to restore vision in people who have lost most or all of their photoreceptors to conditions such as retinitis pigmentosa (RP), regardless of the underlying genetic defect.