Sunday, February 8, 2009
MYOPIARecently, i realised my vision has become blur. I can't see things which are far from me clearly. Mum told me that most probably i have myopia.
Myopia in other words is the near or shortsightedness.
I researched on myopia and got these results.
MYOPIA (Nearsightedness) Myopia occurs when the eye is too long in relation to the curvature
of the cornea. Images fall in front of the retina or too far forward and vision at a distance appears blurred.
On the other hand, HYPEROPIA (Farsightedness) Hyperopia occurs when the eye is functionally too short. The rays of light are focused behind the retina, producing a blurred image. Those who are farsighted may be able to use their focusing muscle and bring the image forward, allowing them to see clearly. This focusing ability becomes difficult with age, and reading glasses or bifocals may be needed
I also found out that there is other types of myopia.
ASTIGMATISM is common. Many people have some degree of astigmatism. This means that the eye is slightly oval and the cornea is shaped like a football rather than a sphere. Those with astigmatism may experience distortion or tilting of images due to unequal bending of the rays of light entering the eye.
To my horror there are many other different types of myopia which are not so common
Degenerative myopia, also known as malignant, pathological, or progressive myopia, is characterized by marked fundus changes, such as posterior staphyloma, and associated with a high refractive error and subnormal visual acuity after correction.This form of myopia gets progressively worse over time.
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Degenerative myopia has been reported as one of the main causes of visual impairment.Myopia with degenerative changes has been described as being very common in certain races and cultures, such as Chinese, Japanese, Korean, Arab, and Jewish people. -
Nocturnal myopia, also known as night myopia or twilight myopia, is a condition in which the eye has a greater difficulty seeing in low illumination areas, even though its daytime vision is normal. Essentially, the eye's far point of an individual's focus varies with the level of light. Night myopia is believed to be caused by pupils dilating to let more light in, which adds aberrations resulting in becoming more nearsighted. A stronger prescription for myopic night drivers is often needed. Younger people are more likely to be affected by night myopia than the elderly.
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Induced myopia, also known as acquired myopia, results from exposure to various pharmaceuticals, increases in glucose levels, nuclear sclerosis, or other anomalous conditions.[8] The encircling bands used in the repair of retinal detachments may induce myopia by increasing the axial length of the eye.
- Index myopia is attributed to variation in the index of refraction of one or more of the ocular media.Cataracts may lead to index myopia.
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Form deprivation myopia is a type of myopia that occurs when the eye is deprived of clear form vision. Myopia is often induced this way in various animal models to study the pathogenesis and mechanism of myopia development.
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I shall go check up my eyes and fix a nice pair of specs if needed =]
11:58 PM
