Vision problems include eye problems and visual disturbances, such as blurred vision, halos, blind spots, floaters, and other symptoms. The most severe form of visual loss is blindness.
Procedures currently help individuals with retinitis
pigmentosa (RP), a disease responsible for roughly 200,000 cases of blindness
in the United States. When light enters the eye through the pupil, it strikes
the retina at the back of the eye and is converted to an electrical signal by
rods and cones. In individuals with RP, these tissues deteriorate, resulting in
full or partial blindness.
The restoration process starts with an image captured
by a small camera attached to a pair of glasses. After streaming through a
video processor, the data is then transferred back through the glasses to a
tiny electrode “sheet” implanted on the retina. These electrodes use electrical
impulses to communicate visual information to undamaged retinal tissue (just as
healthy rods and cones would have done). The result is some degree of sight.
Currently the devices have only 60 electrodes,
compared to more than 2 million in HD televisions, so images are still rough.
This means that if the entire population of New Mexico plus 17,000 of their
relatives were gathered in a field, only 60 would be visible.
The technology has been greatly improved from earlier
16-electrode versions. Before, objects appeared as horizontal lines. Now users
can make out basic shapes; some can see faint reflections and differentiate
between concrete and grass.
“Our near term goal is to get regulatory approval to
market the device in Europe and the United States. This will allow us to
generate revenue to fund the development of next generation prostheses with
greater numbers of electrodes. This should mean more utility for the patients,”
Mech explains.
Researchers from Second Sight will follow project participants for the next three years to track progress. They hope to develop versions with 200 and 1000 electrodes in the future, but so far implant recipients are pleased with results.
"Besides the objective testing that we do to show improvement in visual function, participants are often most excited by personal experiences. One woman saw the moon for the first time in about 20 years," Mech says. "Another can shoot baskets and watch her grandkids play soccer. This is significant."
Is a vision test on your “To Do List”? More than 2.2 million Americans age 40 and older have glaucoma (a group of eye diseases which produce increased pressure within the eye) and the best defense against the disease is an annual vision exam. People usually do not notice signs of glaucoma until they have already lost significant vision.
The elevated pressure in glaucoma is caused by a backup of fluid in the eye, which, over time, may damage the optic nerve. At first, people with glaucoma lose their side vision (peripheral vision). And, if the disease is not treated, vision loss may progress to total blindness. Once vision is lost, it cannot be restored. People with one or more of the following risk factors for glaucoma should have their eyes examined on a regular basis:
To test for glaucoma, your doctor will perform a series of quick and painless tests (eye pressure measurements, dilated eye exams, and sometimes visual field testing) to check for any changes in your eye or in your vision. Through early detection, glaucoma can often be controlled with medications, such as eye drops or pills. If glaucoma does not respond to medication, surgery may be recommended.
glaucoma vision exam optic nerve
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