Retinitis pigmentosa is the most common form of inherited retinal degeneration worldwide. It causes progressive but permanent visual impairment. Patients typically experience night blindness and blind spots in their side vision initially, progressing to central visual disturbance later on, causing difficulties in tasks like reading and watching TV.

Optogenetics is technique whereby retinal cells that usually do not have light-detection ability are able to detect light and restore some level of vision. This is achieved by delivering genes coding for the light-detecting protein, opsin to these cells.