Chapter 2: Descriptive Information
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How Much Field of View Can the Argus 2s system Give Me?
The Argus 2s system delivers electrical signals to your retina
that will allow you to see spots of light. The implant is
designed to give you a visual field of about 3.5 inches by 6.5
inches (9 by 16.5 centimeters) at arm's length, or slightly
larger than a standard 3 x 5-inch index card. However, the
actual size of light you see when the system turns on all the
electrodes together may be larger or smaller.
Each implant has 60 electrodes. Not every electrode in the
array will be able to allow you to see a spot of light on its
own. For most subjects in the clinical trial (28 out of 30) the
number of electrodes that could do this was less than 60. If
fewer than 20 of the 60 electrodes produce spots of light on
their own, your clinician may change the program on the
VPU to turn on groups of electrodes at the same time. A
“quad” is a group of four electrodes next to each other on the
array that stimulate at the same time.
It is possible that not all of your electrodes will be used and,
as a result, your visual field may be reduced. In addition, the
total number of electrodes that provide spots of light can
decrease over time. A single electrode could stop working or
parts of your retina could stop responding to the signal sent
by that electrode.
What will the spots of light look like to me?
Electrodes in the Argus 2s system do not always create
circular spots of light. Sometimes the light looks like a line or
a wedge. During the clinical trial, three subjects were asked
