01-01-2013, 03:18 PM
ARTIFICIAL VISION
HOW WE ARE ABLE TO SEE
For vision to occur,
Scattered light from the object enters through the cornea.
The light is projected onto the retina.
The retina sends messages to the brain through the optic nerve.
The brain interprets what the object is.
Diseases of the Eye
Retinitis Pigmentosa
Hereditary Genetic Disease
Peripheral Rods degenerate
Gradually progresses towards center of eye
Spares the foveal region
Tunnel vision results
Macular Degenaration
Genetically Related
Cones in Macula region degenrate
Loss or damage of central vision
Peripheral Retina spared
Common among old people
BIRTH OF CONCEPT
Neither of these retinal diseases affects the ganglion cells or the optic nerve
This means that if scientists can develop
artificial cones and rods, information could still be sent to the brain for interpretation.
This concept laid the foundation for the invention of the ARTIFICIAL VISION SYSTEM
ASR IMPLANTED
When surgically implanted under the retina, in a location known as the sub retinal space, the ASR is designed to produce visual signals to those produced by the photoreceptor layer.
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
Visual sensations or “phosphenes” can be evoked by electrical stimulation of the different levels of the visual pathway.