what is the cause of hyper myopia ?

Answer 1

it is hyper metropia and in brief it is caused by either :
1) nutritional deficiencies
2) elongation of the eyre
3) weakning of ciliary muscles

hth (hope this helps)

Answer 2

It's a common problem world wide.It's an error of refraction.A great % of people has errors of refraction ,but you have to know 1st what kind of myopia it is simple,congenital or progressive.Simple myopia starts nearly at 14 years old & rarely exceeds -6 diopters,congenital myopia starts at birth ,reaches -10 & is stationary for life & complications are rare.But progressive myopia starts at 5-10 years ,may reach -25 D & is associated with many complications.About treatment,1-Eye glasses a-children ;full correction for far vision2-Contact lenses3-low vision aids in cases with low visiona-telescopic spectacles for distance && for reading b-magnifying lens for reading ****General ttt for progressive myopia;calcium & vitamin D ,near work must be in good illumination,in good position,at a suitable distance,avoid much close work & small faint prints,-Tissue extract as placental extract[not effective]But you are speaking about surgery & it is widespread nowadays-For myopia -2--5 radial keratotomy & Excimer laser keratectomy,For higher myopia excimer laser Intrastromal keratomiliesis,clear lens extraction or phakic low convex or concave intraocular lens,so don't worry & go & see an ophthalmologist to tell you suitable aid that will depend on degree of refractive error of your child & his age.From your question it seems it's congenital myopia & some of his relatives may suffer from similar condition,so don't worry it's as I told you remains stationary for life & complications are rare & thank Allah there is conditions worst than that & treatment is available.

Answer 3

1

Answer 4

agast to see this question from a DR. it is due to elongation of eye ball where the image falls short of retina.

Answer 5

Myopia has been classified in various manners.[1][2][3]

[edit] Etiology

Borish and Duke-Elder classified myopia by cause:[2][3]

* Axial myopia is attributed to excessive, or increase in, the eye's axial length.[4]
* Refractive myopia is attributed to the condition of the refractive elements of the eye.[4] Borish further subclassified refractive myopia:[2]

* Curvature myopia is attributed to excessive, or increase in, curvature of one or more of the refractive surfaces of the eye, especially the cornea.[4] In those with Cohen syndrome, myopia appears to result from high corneal and lenticular power.[5]
* Index myopia is attributed to variation in the index of refraction of one or more of the ocular media.[4]

[edit] Clinical entity

Various forms of myopia have been described by their clinical appearance:[3][6]

* Simple myopia is more common than other types of myopia and is characterized by an eye that is too long for its optical power (which is determined by the cornea and crystalline lens) or optically too powerful for its axial length.[7] Both genetic and environmental factors, particularly significant amounts of near work, are thought to contribute to the development of simple myopia.[7]
* 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.[4] This form of myopia gets progressively worse over time. Degenerative myopia has been reported as one of the main causes of visual impairment.[8] Myopia with degenerative changes has been described as being very common in certain races, such as Chinese, Japanese, Arab, and Jewish people.[9]
* 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.[10]
* Pseudomyopia is the blurring of distance vision brought about by spasm of the ciliary muscle.[11]
* Induced myopia, also known as acquired myopia, results from exposure to various pharmaceuticals, increases in glucose levels, nuclear sclerosis, or other anomalous conditions.[7] The encircling bands used in the repair of retinal detachments may induce myopia by increasing the axial length of the eye.[12]

* Index myopia is attributed to variation in the index of refraction of one or more of the ocular media.[4] Cataracts may lead to index myopia.[13]
* Form deprivation myopia is a type of myopia that occurs when the eye is deprived of clear form vision.[14] Myopia is often induced this way in various animal models to study the pathogenesis and mechanism of myopia development.[14]

[edit] Degree

Myopia, which is measured in diopters by the strength or optical power of a corrective lens that focuses distant images on the retina, has also been classfied by degree or severity:[1]

* Low myopia usually describes myopia of −3.00 diopters or less.[4]
* Medium myopia usually describes myopia between −3.00 and −6.00 diopters.[4] Those with moderate amounts of myopia are more likely to have pigment dispersion syndrome or pigmentary glaucoma.[15]
* High myopia usually describes myopia of −6.00 or more.[4] People with high myopia are more likely to have retinal detachments[16] and primary open angle glaucoma.[17] They are also more likely to experience floaters, shadow-like shapes which appear singly or in clusters in the field of vision.[citation needed] Roughly 30% of myopes have high myopia.[9]

[edit] Age of onset

Myopia is sometimes classified by the age of onset:[1]

* Congenital myopia, also known as infantile myopia, is present at birth and persists through infancy.[7]
* Youth onset myopia occurs prior to age 20.[7]

* School myopia appears during childhood, particularly the school-age years.[18] This form of myopia is attributed to the use of the eyes for close work during the school years.[4]

* Adult onset myopia

* Early adult onset myopia occurs between ages 20 and 40.[7]
* Late adult onset myopia occurs after age 40.[7]