

The Argus II, to give its proper classification, is a retinal prosthesis. Basically, patients undergo a four-hour operation to implant 60 electrodes into the macula — the central region of the retina that provides central and high-resolution vision. These electrodes are connected to an antenna, which connects via a wireless network to a special pair of spectacles that are equipped with a digital camera and a digital signal processor (DSP). The camera captures what the user is looking at, converts the image into signals that the brain will understand, and transmits them to the retinal implant. These signals stimulate the 60 electrodes in such a way as to produce electrical signals that can be understood by the brain. As you can imagine, an array of 60 electrodes doesn’t provide a very high resolution (10×6!), but it’s a huge step up from complete blindness.

Now, as you can imagine, upgrading the retinal implant is rather hard — presumably, you’d have to spend a few hours digging it out (if that’s even possible), and then a few more hours replacing it. Furthermore, if Second Sight changes the hardware, it would need to be re-certified by the FDA, which could take years. A software update, however, doesn’t require FDA approval (though in the future, as implants become more invasive, that will probably change).

Through a software update called Acuboost, Second Sight says it can improve the resolution, focus, and zooming of images seen by Argus II users. The latest version of the software, which is still being beta tested before being rolled out to users, also has automatic brightness adjustment and color recognition. Creating color vision is interesting, because technically the implant users don’t have any color vision (those cells were destroyed by the degenerative eye disease that led to their blindness). It turns out, though, that specific frequencies and delays in electrode stimulation — it’s different for every user — can cause the perception of color. This on its own is quite an exciting breakthrough when it comes to understanding the optic nerve’s encoding scheme, which we still know so little about.

Second Sight is also looking at upgrading the hardware in spectacles, but again that would trigger a couple of years of jumping through regulatory hoops. There’s no timeline on Acuboost being rolled out to users, but Second Sight hopes to do it “shortly.”

Meanwhile, over in Germany, the Alpha IMS bionic eye has recently received European regulatory approval. Alpha IMS is a self-contained bionic eye that grants vision by using light that actually enters the eye, rather than using an external camera, thus making it a lot more flexible than the Argus II. Alpha IMS has a massive number of electrodes — 1,500 vs. 60 on the Argus — providing fairly high-resolution sight to its users. In short, Alpha IMS is amazing — but for the foreseeable future, you’ll have to visit Europe if you want to have one installed.