|The Argus 2 implant is the successor to Argus 1. Both were created by the same
company, Second Sight. Both were created for the same purpose: To restore sight
to the blind. Like its predecessor, Argus 2 is a complex arrangement of implanted
electrodes, implanted data receiver and spectacles. Where it offers improvement
over its predecessor is that Argus 1 could only offer 16 electrodes in a 4 x
4 array. In the same area on the back of the retina, Argus 2 offers 60 electrodes
in a 10 x 6 array.
Otherwise, it is exactly like its predecessor. It consists of a tiny camera
and transmitter mounted in the rims of a pair of inconspicuous spectacles, an
implanted receiver under the skin to one side of the eye, which receives the
output of the camera on that side, and connects via fine wires to an electrode-studded
array secured to the retina with a microtack the width of a human hair. A wireless
microprocessor and battery pack worn on the belt power the entire arrangement.
As with its predecessor, this sounds quite a lot like the setup used in virtual
sight. This is not quite the case.Argus connects to the retina of the eye, whereas
virtual sight connects to the optic nerve directly. As a result, Argus requires
a natural eyeball to still be in place, and cannot work with those lacking such.
Because it is the same setup as the previous device, much of the hardware remains the
same. The spectacles in particular can be used with either device, as in both
cases, the tiny cameras are capable of recording much more information than
the Argus devices can process. The real advantage the Argus 2 has however, is
because it offers a 10 x 6 'pixel' display rather than a 4x6 one, is there is
enough information now to distinguish simple objects like a human head.
Still, this amount of data is still alien to the human visual system. Normally
the human retina processes 8.75 megapixels worth of data per second. even updating
ten times a second, 600 bytes is nothing next to that. As with the Argus 1,
patients have to learn how to see all over again, to interpret the visual patterns
produced into meaningful images.