Press the l key to open the language menu.
Skip Main Navigation and go to Content

The retinal implant provides stimulation to induce visual perception in blind individuals.


Cornea  The clear outer part of the eye’s focusing system, located at the front of the eye.


Degenerative Retinal Disease A disease, such as retinitis pigmentosa, in which the function or structure of the affected tissues or organ will progressively deteriorate over time.


Epiretinal Prosthesis – An implant that is placed on top of the retina versus a “subretinal” that sits underneath the retina.


Fovea – The centre of the macula; it gives the clearest vision and is used in reading.


Iris – The coloured part of the eye located behind the cornea that regulates the amount of light entering the eye like the shutter of a camera.


Lens – A clear disc in the eye located behind the iris that helps focus light or an image on the retina.


Macula  The small, sensitive area of the retina that provides central vision. It is located in the centre of the retina and contains the fovea.


Optic Nerve – A bundle of more than one million nerve fibers that carry visual messages from the retina to the brain.


Pupil – A hole in the centre of the iris that allows light to enter the eye and reach the retina.


Photoreceptors Cells in the retina that connect with other nerve cells to transmit visual information to the brain. Rod photoreceptors control night vision while cone photoreceptors are involved in color vision.


Retina – A thin layer of cells at the back of the eyeball that convert light into nerve impulses that travel to the brain.


Retinitis Pigmentosa  Retinitis pigmentosa (RP) is a disease that leads to degeneration of the rods and cones of the retina; it is one of the leading causes of inherited blindness. Symptoms may appear at adolescence, but severe vision problems do not normally occur before early adulthood. In the early stages of the disease, people with RP experience loss of night vision and more difficulty seeing in low-light conditions. As the disease progresses, RP sufferers begin to lose peripheral vision and develop ‘tunnel vision’. In the most advanced stages, a person with RP may become completely blind. Other forms of RP and related diseases include Usher syndrome, Leber’s congenital amaurosis, rod-cone disease, and Bardet-Biedl syndrome, among others.


Credit: National Eye Institute, National Institutes of Health for certain glossary terms