Around one million people in britain suffer from two of the most common forms of blindness : macular degeneration and retinitis pigmentosa .
在英国大约有一百万人患有两种最普遍的失明疾病:视网膜黄斑变性和色素性视网膜炎。
Each diode stimulates the nerve cells that have their endings in the retina-unlike the photoreceptors , these cells are unharmed by retinitis pigmentosa-and the nerve cells in question then relay their individual signals to the brain via the optic nerve .