Written on Mar 2, 2009 at 9:53 PM by LASIK Guider
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Unaccommodated lens on the left versus accommodated lens on the right

Accommodation is the natural ability of the eye to change its refractive power in order to see clearly objects at different distances.



Throughout life, human beings pass through many normal aging processes. As a result, many conditions may develop and affect the functions of your body. Presbyopia is one of these conditions that occur as the potency of accommodation decreases with age.




Mechanism of Accommodation

The secret behind the ability of the eye to accommodate lies in the structure of the crystalline lens. When we are young, the lens is flexible and can vary its refractive power by changing shape from being spherical to be more oval and back again when needed. With age, the lens loses its elasticity and cannot increase its change its , thus the ability of the eye to accommodate gradually decreases. Only when this interferes with comfortable near work (e.g., reading) that we speak of presbyopia.




Symptoms and Signs of Presbyopia:

In most persons, presbyopia occurs between 40 and 45 years of age. It occurs earlier in farsighted persons and later in nearsighted persons. At first, presbyopic persons complain of eyestrain, headache and unclear small prints on reading in artificial light at night. Then, the reading becomes impossible also in day light. Finally, the reading becomes impossible.




Diagnosis and Treatment of Presbyopia:

Eye care professionals usually correct presbyopia by prescribing a convex lenses in the form of . These positive lenses help the eye to focus on close objects during close work. The strength of the reading glasses may need to be increased with age.



Sometimes presbyopia associated with other refractive error such as myopia, hyperopia, or astigmatism. In this situation the person will need two pairs of glasses one for distance vision and another for near vision. An alternative is to combine both in one bifocal glasses used for both distant and near vision.



The surgical correction of presbyopia is still in its infancy. However, presbyopia can be taken care by using the idea of monovision where one is corrected for distance vision and other for near vision.



The full series of LASIK Vision Correction Explained tutorials are , , , ,, , , , and .

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