Task 2 : The Eye Gan Jia Jie 2A409

Short-sightedness/Myopia  It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it.  This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object.

Short-sightedness:causes  Axial myopia: It is attributed to an increase in the eye's axial length.  Refractive myopia: It is attributed to the condition of the refractive elements of the eye. Borish further sub-classified refractive myopia  Curvature myopia : It is attributed to excessive, or increased, curvature of one or more of the refractive surfaces of the eye, especially the cornea. In those with Cohen syndrome, myopia appears to result from high corneal and lenticular power  Index myopia: It is attributed to variation in the index of refraction of one or more of the ocular media

Longsightednes/Hyperopia  It is a defect of vision caused by an imperfection in the eye.  causes difficulty focusing on near objects, and in extreme cases causing a sufferer to be unable to focus on objects at any distance

Long-sightedness cont.  As an object moves toward the eye, the eye must increase its optical power to keep the image in focus on the retina. If the power of the cornea and lens is insufficient, as in hyperopia, the image will appear blurred.

Long-sightedness:Causes-AGE  Long-sightedness can occur at any age, but it is often more noticeable after the age of 40.  Age-related long-sightedness is known as presbyopia. It develops when the lens in your eye becomes stiffer.

Long-sightedness:Causes- Genetics  Long-sightedness is thought to be a condition that some people inherit from their parents.  However, with the exception of a rare form of hyperopia called nanophthalmos, specific genes for long-sightedness have yet to be identified and further research is needed.

Management  Primary options: Glasses, contact lenses, refractive surgery

Glasses  using optical lenses bringing the image a viewer closer so that it can be focused by their myopic eyes.  Reading glasses can also be worn during near work to decrease the strain on the eye, especially when already wearing corrective lenses, as they work in the opposite fashion to normal lenses.

Management cont.  For people with significant long-sightedness, contact lenses can be the best form of correction as they provide better vision and may be preferable to wearing thick glasses. Contact lenses can be made from different materials and can be disposable or non-disposable.

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