Artificial Silicon Retina (ASR)

The ASR is a silicon chip
2 mm in diameter and 1/1000 inch in thickness.

It contains approximately
3,500 microscopic solar cells
called "microphotodiodes,"
each having its own stimulating electrode.

These microphotodiodes
are designed to convert the light energy
from images
into
thousands of tiny electrical impulses
to
stimulate the remaining functional cells
of the retina
in patients with AMD and RP types of conditions.

     2 mm ASR     
   lying on top of a penny   

The ASR
is powered solely by incident light
and does not require the use of
external wires or batteries.
When surgically implanted
under the retina,
in a location known
as the sub retinal space,
the ASR is designed to produce
visual signals
similar  to those produced by the
photoreceptor layer.

Magnified image of an ASR

From their sub retinal location these artificial "photoelectric" signals from the ASR are in a
position to induce biological visual signals in the remaining functional retinal cells
which may be processed and sent via the optic nerve to the brain.

In pre-clinical laboratory testing,
animal models, implanted with the ASRs
responded to light stimuli with retinal electrical signals (ERGs)
and sometimes brain-wave signals (VEPs).

The induction of these biological signals
by the ASR
indicate that visual responses had occurred.

     ASR implanted in eye