Posts Tagged ‘retina’

Retina and Vision

Vision loss is one of the greatest losses that one can suffer. Retinal damage is one of the leading causes of vision loss. The retina is a tissue that is multi layered and which is present at the rear of the eye. It is about 0.5mm in thickness. The Retina can be affected with various kinds of problems and the treatment varies depending upon the nature of the problem. Retinal surgery comes as a boon to many who are bordering on losing their precious vision. But this does not necessarily mean that every patient’s original vision would be restored. Some would have to bear with the loss of partial vision for life.

Researchers are also contemplating and studying retinal transplant as an option to restore lost vision. Studies have shown encouraging results and this could soon be a reality. Electronic retinas have also been considered and researchers are trying out the benefits of this type of retina to help patients get better vision. Retina is a nerve tissue and damage to the retina can lead to many eye problems. Macular degeneration and Retinitis Pigmentosa are common age related problems. This can lead to blindness if not treated in time. Degenerative diseases are not the only ones that affect the retina and thereby vision. The retina can also be affected due to malnutrition. A lack of Vitamin A in ones diet can at a later stage be the cause for nightblindness.

The retina can be said to be a very crucial part of the eye and any sort of problem with the retina can lead to vision loss if not treated on time. Surgery can help patients with retinal problems and this can help in slowing down the Vision loss process. The retina is quite vulnerable to damage by the free radicals. Diseases that affect the retina are supposed to be the leading cause of loss of vision. The rods and cones which help in sensing the light get affected and this in turn makes the patient unable to see.

Millions of patients the world over are affected by retinal problems. Over the years the damage that is inflicted upon the retina is unfathomable. This leads to many a problem at a later stage and finally ends up in Vision loss. The eyes have to taken care of well for it has to last a lifetime and an eye specialist needs to be consulted regularly so as to arrest any problem at the earliest.


What is Retina?

The retina is that portion of the innermost part of the eye which is light sensitive. The retina is like a camera as it helps in creating the image. The photoreceptor cells, cones and the rods are the ones responsible for receiving the light and this is sent to the brain through the optic nerves by transforming it into image forming signals. Actually the optic nerve can be said to be a central tract which is the connecting factor of the retina and the brain. Another important feature of the retina is that it is the only part which belongs to the central nervous system (CNS) which can be directly imaged.

The retina is made up of many layers, 10 to be precise. The different layers from the innermost to the outer one are listed below:

  1. Inner Limiting Membrane
  2. Nerve Fiber
  3. Ganglion Cell: the one responsible for producing the optic nerve fibers.
  4. Inner Plexiform Layer
  5. Inner Nuclear Layer
  6. Outer Plexiform Layer
  7. Outer Nuclear Layer
  8. External Limiting Membrane
  9. Photoreceptor Layer
  10. Retinal Pigment Epithelium

The retina is quite a complex portion of the eye. An adult’s retina is said to have a diameter of about 22 mm. the retina constitutes 72% of the entire area of a sphere. The retina is made up of 75-150 million rods and 7 million cones, figures which are even difficult to fathom. An image is created with the functioning of both the cones and the rods. The cones are the ones that react when bright light falls and decides upon high resolution and color vision whereas the rods react to dim light and arbitrate regarding lower resolution vision, night vision and also black and white vision. Cones that are sensitive to light that are green, red and blue in color are absent in certain individuals which causes color blindness problems and various other color vision deficiencies. Since humans have 3 cones as compared to other mammals which have two (they lack the red sensitive cone), the color vision of humans becomes superior. The retina functions in a truly amazing pattern by compressing the image size to fit the scope of the optic nerve.

The retina is also prone to various diseases such as macular degeneration, retinal separation, retinoblastoma and many others. There are various instruments and treatment methods available today so as to diagnose and treat these problems at the earliest. The retina is a crucial part of the eye and for good vision one would need a healthy retina lifelong.

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