Is the onset of presbyopia depends on amplitude of accommodation?
Presbyopia - MCQS
Question: 1
1. The onset of presbyopia depends on:
a. the size of the pupil
b. task required
c. sex of the patients
d. the refractive state of the patients
e. amplitude of accommodation
Answer:
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A. True
B. True
C. False
D. True
E. True
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Reference:
Presbyopia
During middle age people experience blurred vision when reading or looking at objects close up.
Presbyopia is a natural part of the ageing process resulting in a gradual decline in the ability to focus on close objects or to see small print. Presbyopia is due to the lens losing its flexibility, making it more difficult to focus on objects up close. This condition becomes evident in almost all people over the age of 45.
Causes of Presbyopia
In order for the eye to focus on an object, the lens changes shape depending on the distance of the object. For the eye to focus on an object up close, this will require the ciliary muscle (which controls the shape of the lens) to contract inorder for the lens to thicken and increase the focusing power to the eye. To focus on something at a distance the ciliary muscle relaxes, which causes the lens to flatten.
With the natural ageing process the eye's lens stiffens, and it is less able to focus on objects up close. These changes occur within the proteins in the lens, causing the lens to become harder and less elastic. Age-related changes also take place in the ciliary muscle surrounding the lens.
Diagnosis of Presbyopia
As presbyopia comes on gradually with age (usually in the 40's onwards) most people don't notice small vision changes and delay seeking professional help until the focusing problems interfere with daily life. Many optometrists joke that patients seek help only when their arms become "too short," as they are unable to hold printed pages far enough away from them inorder to see clearly.
Presbyopia will be diagnosed by an optometrist, ophthalmologist or eye care professional who will test your vision
If the diagnosis is presbyopia, a test will be undertaken to determine the extent of the focusing problem and the appropriate lens prescription.
Treatments for Presbyopia
The most common form of treatment for presbyopia is with prescription or reading glasses. Long sighted glasses wearers with presbyopia will need to use bifocals. These are lenses for both distance vision and for observing objects close up.
Bifocal contact lenses are another option which provide the convenience of contact lenses and the ability to see close up as well as far away.
Another popular alernative is monovision where one eye is used for viewing in the distance, and the other eye for viewing things up close.
It is also possible to postpone or slow down the hardening of the lens through good nutrition, aerobic exercise and a healthy lifestyle.
Refractive surgery for presbyopia is an option that many people enquire about, however many procedures are in investigational stages. There is a lot of disagreement about the causes of presbyopia, and so many of the new procedures have little incommon with each other as they treat different possible causes.
Procedures such as monovision LASIK eye surgery works well for many patients regardless of the cause of presbyopia.
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