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ARTIFICIAL RETINA RRS feed

  • Question

  • Imagine a world without light, horrible isn’t it? This the same world in which many people around the globe are living in – the Black world. The vision is a healthy reproduction of the light patterns reflected from the surrounding. The light sensing element in the human body is the retina in the eye. The retina receives light from objects and converts them into electrical signals to be interpreted by the brain. A defect to the retina can lead to partial or total visual impairment. There are two types of retinal degenerative disease: Retinitis pigmentosa (RP), and Age-related macular degeneration (AMD). These diseases are due to damaged photosensitive layer and mucular layer respectively. The alternative to such retinal defects is artificial retina. Artificial retina is a silicon microchip implanted in the eye that stimulates the retinal cells, allowing them to send visual images to the brain. It contain silicon micro arrays which are responsible for the signal conversion. A detailed description and explanation on the above has been presented in this paper. It discusses how the image is constructed and transmitted from the eye to the brain.

    INTRODUCTION

    The beauty of the world lies in its rainbow like colors. The eye thus brings color to our life. The imagination of a black and white world itself raises the h

    hairs on our body. So, this can tell us about the plight of the innumerable people suffering from eye defects.

    “Necessity is the mother of all inventions.”

    With the advent to time, man has almost replaced half of the body parts with artificially engineered ones. The cyborg is the best example of this. The field of optics has taken a big leap with the discovery optoelectronics, and one such example is the artificial retina. The detail explanation has been presented in the following passages.

    Friday, March 23, 2007 8:49 AM

Answers

  • RETINA

    The retina is complex in itself. This thin membrane at the back of the eye is a vital part of your ability to see. Its main function is to receive and transmit images to the brain. These are the three main types of cells in the eye that help perform this function:

    ·                                 Rods

    ·                                 Cones

    ·                                 Ganglion Cells

    There are about 125 million rods and cones within the retina that act as the eye's photoreceptors. Rods are the most numerous of the two photoreceptors, outnumbering cones 18 to 1. Rods are able to function in low light (they can detect a single photon) and can create black and white images without much light. Once enough light is available (for example, daylight or artificial light in a room), cones give us the ability to see color and detail of objects. Cones are responsible for allowing you to read this article, because they allow us to see at a high resolution

    The information received by the rods and cones are then transmitted to the nearly 1 million ganglion cells in the retina. These ganglion cells interpret the messages from the rods and cones and send the information on to the brain by way of the optic nerve.

    Friday, March 23, 2007 8:50 AM
  • RETINAL DISEASES

    There are two types of retinal degenerative disease:

    ·                                 Retinitis pigmentosa (RP)

    ·                                  Age-related macular Degeneration (AMD)

    RETINITIS PIGMENTOSA (RP)

    It is a general term for a number of diseases that predominately affect the photoreceptor layer or “light sensing” cells of the retina. These diseases are usually hereditary and affect individuals earlier in life.

    Injury to the photoreceptor cell layer, in particular, reduces the retina’s ability to sense an initial light signal. Despite this damage, however, the remainder of the retinal processing cells in other layers usually continue to function. 
        

    Although different forms of RP may affect different specific areas of the visual field, most RP affects the mid-peripheral vision first and—sometimes—progresses to affect the far-periphery and the central areas of vision. 

    The narrowing of the field of vision into “tunnel vision” can sometimes result in complete blindness. Some specific forms of RP and related conditions include Usher’s Syndrome, Leber’s Congenital Amaurosis, Stargardt’s Disease, Cone-Rod Dystrophy, Best’s Disease, Choroideremia, and Gyrate Atrophy.

    Friday, March 23, 2007 8:50 AM

All replies

  • RETINA

    The retina is complex in itself. This thin membrane at the back of the eye is a vital part of your ability to see. Its main function is to receive and transmit images to the brain. These are the three main types of cells in the eye that help perform this function:

    ·                                 Rods

    ·                                 Cones

    ·                                 Ganglion Cells

    There are about 125 million rods and cones within the retina that act as the eye's photoreceptors. Rods are the most numerous of the two photoreceptors, outnumbering cones 18 to 1. Rods are able to function in low light (they can detect a single photon) and can create black and white images without much light. Once enough light is available (for example, daylight or artificial light in a room), cones give us the ability to see color and detail of objects. Cones are responsible for allowing you to read this article, because they allow us to see at a high resolution

    The information received by the rods and cones are then transmitted to the nearly 1 million ganglion cells in the retina. These ganglion cells interpret the messages from the rods and cones and send the information on to the brain by way of the optic nerve.

    Friday, March 23, 2007 8:50 AM
  • RETINAL DISEASES

    There are two types of retinal degenerative disease:

    ·                                 Retinitis pigmentosa (RP)

    ·                                  Age-related macular Degeneration (AMD)

    RETINITIS PIGMENTOSA (RP)

    It is a general term for a number of diseases that predominately affect the photoreceptor layer or “light sensing” cells of the retina. These diseases are usually hereditary and affect individuals earlier in life.

    Injury to the photoreceptor cell layer, in particular, reduces the retina’s ability to sense an initial light signal. Despite this damage, however, the remainder of the retinal processing cells in other layers usually continue to function. 
        

    Although different forms of RP may affect different specific areas of the visual field, most RP affects the mid-peripheral vision first and—sometimes—progresses to affect the far-periphery and the central areas of vision. 

    The narrowing of the field of vision into “tunnel vision” can sometimes result in complete blindness. Some specific forms of RP and related conditions include Usher’s Syndrome, Leber’s Congenital Amaurosis, Stargardt’s Disease, Cone-Rod Dystrophy, Best’s Disease, Choroideremia, and Gyrate Atrophy.

    Friday, March 23, 2007 8:50 AM