  Current visual implants still provide very low resolution and limited field
of view, thus limiting visual acuity in implanted patients. Developments of new
strategies of artificial vision simulation systems by harnessing new
advancements in technologies are of upmost priorities for the development of
new visual devices. In this work, we take advantage of virtual-reality software
paired with a portable head-mounted display and evaluated the performance of
normally sighted participants under simulated prosthetic vision with variable
field of view and number of pixels. Our simulated prosthetic vision system
allows simple experimentation in order to study the design parameters of future
visual prostheses. Ten normally sighted participants volunteered for a visual
acuity study. Subjects were required to identify computer-generated Landolt-C
gap orientation and different stimulus based on light perception,
time-resolution, light location and motion perception commonly used for visual
acuity examination in the sighted. Visual acuity scores were recorded across
different conditions of number of electrodes and size of field of view. Our
results showed that of all conditions tested, a field of view of 20{\deg} and
1000 phosphenes of resolution proved the best, with a visual acuity of 1.3
logMAR. Furthermore, performance appears to be correlated with phosphene
density, but showing a diminishing return when field of view is less than
20{\deg}. The development of new artificial vision simulation systems can be
useful to guide the development of new visual devices and the optimization of
field of view and resolution to provide a helpful and valuable visual aid to
profoundly or totally blind patients.
