Generally speaking, there are three types of blindness. The first is optical blindness where light is prevented from passing through the cornea. The cornea, aqueous humor, lens and vftreous humor must be transparent, or nearly so, if the person is to see well. Anything that clouds any of these media Witerferes with visn. Corneal transplantation, keratoprosthesis lirplantation, cataract surgery with intraocular lens implantation and vitreoretinal procedures can resolve most cases of this type of blindness. The second Is retina Blindness due to photo receptor damage or retina detachment, such as Retinitis Pigmentosa ( RP ). Every year, blindness disease due to retinal degeneration relegates thousands of people to painfully dark lives. The third optical nerve blindness resulting from injury or disease of the Optical nerve. Scientists have searched every discipline to find eftective methods of treating blindness, such as using aids based on conversion of the optical image, to auditory or tactile StimUk. However, the Umited performance of such equipment and difficulties in training patients have seriously harrçered praaI applicahons. A great edification has been given by the discovery of Foerster (1929)1 and Krause & Schum (1931)2, who found that the electrical stimulation of the visual cxrtex evokes the perception of a snI spot light called phosphene' in both blind and sighted subjects. According to this principle, It is possible to Invite artificial vision by using stimulation with electrodes placed on the vision neural system, thereby developing a prosthesis for the blind that migt4 be of value in reading and mobility. In fact, a number of investigators have already exploited this phenomena to produce a funtional visual prosthesis, bringing about great advances in this area.
[1]
S. Thanos,et al.
Regenerative and proliferative capacity of adult human retinal cells in vitro
,
2004,
Graefe's Archive for Clinical and Experimental Ophthalmology.
[2]
W. Dobelle,et al.
Phosphenes produced by electrical stimulation of human occipital cortex, and their application to the development of a prosthesis for the blind
,
1974,
The Journal of physiology.
[3]
G S Brindley,et al.
The visual sensations produced by electrical stimulation of the medial occipital cortex.
,
1968,
Journal of Physiology.
[4]
P. E. K. Donaldson,et al.
A vacuum centrifuge for void-free potting of implantable hybrid microcircuits in silicone
,
2006,
Medical and biological engineering.
[5]
Microfabrication technology for development of chronic neural information transducers
,
1986,
1986 International Electron Devices Meeting.
[6]
Wen H. Ko,et al.
Feasibility study of the engineering problems in a multi-electrode visual cortex stimulation system
,
2006,
Medical and biological engineering.
[7]
Kensall D. Wise,et al.
A Low-Capacitance Multielectrode Probe for Use in Extracellular Neurophysiology
,
1975,
IEEE Transactions on Biomedical Engineering.
[8]
D L Guyton,et al.
Capacitor Electrode Stimulates Nerve or Muscle without Oxidation-Reduction Reactions
,
1973,
Science.
[9]
T. R. Anthony,et al.
Deep‐diode arrays
,
1976
.