AFP/ MANILA BULLETIN The technique known as optogenetics, which has been developed in the field of neuroscience over the last 20 years, involves genetically altering cells so they produce more light-sensitive proteins. In some cases of blindness, known as inherited photoreceptor diseases, light-sensing cells in the retina that use proteins to deliver visual information to the brain via the optic nerve progressively degenerate. Scientists in Europe and the US recruited a man who had lost his sight due to an inherited photoreceptor disease 40 years ago and began treating him with optogenetic techniques. This involved injections in his eye and several months of stimulation with light emitting goggles, which transformed images of the visual world into light pulses projected into the retina in real time.