Profoundly blind people could get their best shot yet of restored vision with a more advanced "bionic eye", researchers have announced.

　　研究人员宣布，完全失明的人可以试一试用一种更先进的"仿生眼"恢复视力。

　　Trials of the new retinal prosthesis will begin shortly, following the success of a prototype that has enabled six blind people to see again.

　　在6名盲人试用人造视网膜雏形机后视力成功恢复之后，针对新型视网膜修复术的试验将在不久将来进行。

　　Within a few weeks all could detect light, identify objects and even perceive motion again. For one patient, this was the first time he had seen anything in half a century, after his sight was destroyed by retinitis pigmentosa, a virus that attacks retinal cells.

　　几周之内，这6名盲人都能察觉到光线，辨别物体甚至还能察觉动作。其中一个盲人，自从他的视力被色素性视网膜炎（一种侵袭视网膜细胞的病毒引起的）所损坏后，这是他半个世纪以来，首次有了视觉。

　　"We hoped they might get some sense of light and dark, but it's really amazing how much they can see - how the brain is able to fill in the gaps," says Mark Humayun, who carried out the implant surgery and developed the device with colleagues at Doheny Eye Institute at the University of Southern California in the US.

　　“我们本希望让病人可以感知光明与黑暗，但他们视力恢复得如此好，真令人惊奇——他们的大脑是怎么与仪器完全联接融合的呢？”美国南加利福尼亚大学Doheny眼科学院的Mark Humayun说。他与他的同事们研发了人造视网膜并主刀植入手术。

　　For the technique to work, the patient must still have some functioning ganglion cells - nerve cells that transmit visual information from the retinal cells to the optic nerve - as well as a fully-functioning optic nerve. A tiny electronic pad is placed onto the retina of one eye, so that the electrodes are in direct contact with the ganglion cells. Each of the devices' 16 electrodes can stimulate 20 to 30 cells.

　　为了该技术能够应用，盲人身上必须安装一些官能神经节细胞——把视觉信息从视网膜细胞传导到视神经的神经细胞。这就象是整套视神经的工作原理一样。一个微小的电子衬垫被放置在单侧眼睛的视网膜上，这样电极就可以与神经节细胞直接接触了。仿生眼的16个电极中，每一个都能激发20到30个视网膜细胞。

　　Real-time vision

　　The user wears a pair of glasses that contain a miniature camera and that wirelessly transmits video to a cellphone-sized computer in the wearer's pocket. This computer processes the image information and wirelessly transmits it to a tiny electronic receiver implanted in the wearer's head.

　　实时视力

　　使用者佩戴一副装有小型摄像机的眼镜，将视频信号无线传输到随身携带的掌上电脑中。这台电脑处理完图像信息，同样以无线传输的方式将信号传输给植入携带者脑部的微型电子接收器。

　　The received in the implanted chip, the digital information is transformed into electrical impulses sent into the ganglion cells. From there, the brain takes over as the information travels down the optic nerve to the visual cortex at the back of the brain. The whole process occurs extremely rapidly, so that patients see in real-time. This is important any noticeable lag could stimulate the "vestibular-ocular reflex", making people feel dizzy and sick.

　　植入芯片接收到数字信号后，将其转化为电气脉冲，并发给神经节细胞。在大脑的控制下，视觉信息从神经节细胞传输给视神经，再传输给大脑后部的视觉大脑皮层。整个过程发生得极快，所以病人感觉就是实时的。重要的是，任何明显的视觉滞后都可能引起"前庭视觉反射"，那样的话，会让人感到头晕恶心。

　　Humayun's team is about to embark on a new trial of an improved device, which they will fit into 50 to 75 people aged over 50, who are also blind as a result of retinitis pigmentosa. The trial will involve monitoring them for two years and will take place in five centres across the US.

　　Humayun的研究小组即将对改良“仿生眼”进行新一轮的试验，他们将把改良后的“仿生眼”用于50到75名因色素性视网膜炎而失明的年过半百的人身上。试验将包括对受测试者历时2年的监测，并同时在全美的5个试验中心进行。

　　Field of view

　　The first implant had just 16 electrodes on the retinal pad and, as a result, visual information was limited. The new device has 60 electrodes and the receiver is shrunk to one-quarter of the original's size. It is now small enough to be inserted into the eye socket itself. The operation to fit the implant will also last just 1.5 hours, down from 7.5 hours.

　　视野

　　首个植入芯片在视网膜衬垫上只有16个电极，导致视觉信息受到限制。新型“仿生眼”有60个电极，而接收器也缩小到原来尺寸的1/4。这样，接收器的大小就适合于植入眼窝中了。植入手术会耗时1.5小时，不会超过7.5小时。