An artificial retina that can restore some vision to people blinded by a rare genetic disease has been given the official go-ahead after successful trials. European regulators have approved the development after 30 patients were tested - ten of whom were from Britain. Scientists say it marks a major step forward in bionic eye technology as it proves electronic implants can be used to restore sight. However, it does not come cheap and is only available to private patients at a cost of £50,000. Training to use the gadget also costs about £10,000. Second Sight, the company which makes the technology, hopes that it will become available on the NHS. The implants are designed to help people with retinitis pigmentosa, (RP) a degenerative and incurable disease which affects about one in 4,000 people. In RP,  the light receptor cells in the retina die off. The rod photoreceptors (which provide black and white vision) are mostly affected but sometimes the genetic disorder affects the cones or colour vision photoreceptors. As the retina slowly degenerates and gradually loses its ability to transmit images to the brain, there is a progressive loss of vision. The new technology called Argus II uses a camera fixed on dark glasses to send signals to 60 electrodes implanted on the retina, which relays them to the optic nerve, according to The Times. Blind patients first need an operation to fit the implant along with a radio receiver and electrode pad which stimulates relevant cells in the retina. Once this process is complete, they can use the camera to see light, motion and colour, make out large objects and even read large letters on a screen. A tiny computer converts images into electrical pulses which are transmitted to the implant and the electrodes then turn them into pixels of light. Lyndon Da Cruz, a consultant ophthalmic surgeon at Moorfields Eye Hospital in London told the newspaper: 'This demonstrates that plugging in technology to the neural structure of the eye is possible, and that this can integrate stably over a long period. 'Now we have something that works we can begin to think about how to make it better.' Gregoire Cosendai, vice president of Second Sight, said the company was expected to start selling the technology in the summer.