I have severe nearsightedness (-7 diopter) and I wanted to know what the cause is primarily?

Question

Is it because of the lense inside my eye is defective??
or the muscles that adjust the lense have something wrong with them?
or my cornea is shaped different (too steep or whatever)?
or is it because my eyeball is too long so the image is unable to focus on the retina?
or could it be either of these or a combination...
I do know that the cornea and the lense work together to focus the image on the retina and the muscles work to fatten or elongate the lense in order to focus the image.
I have been researching this a lot but haven't been able to find the answer so if anyone knows I will greatly appreciate an answer!!
Also, if you have an tips on how to prevent my vision from getting worse, let me know.

Answer 1

It isn't possible to know the exact cause for you without measuring your individual eyes with a variety of tests. Generally, myopia is due to a mismatch between the refractive (light bending) elements of the eye and the total length of the eye.

The refractive elements include the front and back curves of the cornea, its thickness and density and the front and back curves of the lens, its thickness and density. The total length of the eye consists of the corneal thickness, anterior chamber depth, lens thickness and posterior chamber depth. If the total power of the eye has a focal length that is shorter than the total length of the eye, you are myopic.

You could have tests done to measure these various elements and then compare the results to "average" eyes and possibly determine if any one element is more unaverage than the others and thus the cause of your myopia.

As the size and shape of these various elements are determined by your individual genetic make up, there is no way to prevent your myopia from increasing. Most myopes stop getting worse between the ages of 16 and 25.

Answer 2

There can actually be a number of reasons why.

Yes it can be all of the ones that you listed, or just one. Sometimes your vision is heriditary. You have a mother, and a father, and then you will have a child that wears glasses. Other times it is the shape of your eye which is called astigmatism. Astigmatism is when your eye is not shaped like a shphere, or a basketball, but it is shaped like a football. You can tell is you have astigmatism because you will have a cylinder power on your prescription. If your prescription is just a -7.00 then you do not have any astigmatism. If you have a prescription lijke -.25 -7.00 X 45 then you have astigmatism.

If you are just a -7.00 then you are myopic which means that you can not see images very well from a distance, and your glasses assist with you viewing these images. Myopia occurs when your eye is enlongated, and the light focus on the fron of the eye instead of directly on the retina.

So to answer you question, it seems as if you are myopic, since you didn't mention astigmatism, which means that your eye is elongated, and light does not focus correctly on your retina. Wearing your glasses causes the light to focus correctly where it should focus. It's hard to tell you rather or not your vision will get worse. You will have to look at your history of prescriptions to see this. Has there been an increase in your prescription or have you stayed the same. This part of your question you will need to talk to you eye doctor.

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Answer 3

Having suffered the same thing, I can tell you it is simply that your eye is shaped like as oval, instead of round & the light doesn't hit the retina as it should. Yes, it does get worse with age, but the new wave lasix surgery corrects this problem very well! It was a miracle for me! Very few side effects - if any, & it takes only seconds for the surgery! Save your$$$$!

Answer 4

The actual primary cause of nearsightedness or farsightedness is HEREDITY.... you inherit the problems from your parents---if your parents were both nearsighted, chances are all their kids will be nearsighted as well... if they are farsighted... then all should be farsighted.. IF one parent is near and one parent is farsighted, you could have what MY family has----one nearsighted child, one farsighted and one with perfect vision.... I'm the nearsighted one.... my older brother is farsighted and my younger brother never wore glasses... Oh and my son is nearsighted... of COURSE it's also because of the shape of the eye and all that and where the light hits on the lens and retina, but heredity has an awful lot to do with MOST of the things we have.

Answer 5

In response to your question, I thought I would do some research on prevention of myopia since I didn't know much about it. I found an interesting website listed below that tells a much different story than most common knowledge and than what your eye professional would tell you.

Most information found in books or on websites will explain why the eye cannot focus on distant objects. In medical terms it is called myopia which is derived from the Greek meaning to squint. An image needs to be at it's point of focus on the retina to be a clear image. If the eyeball were spherical or round, distant objects would be focused on the retina without any visual aids and closer objects are focused by accommodation or fattening of the crystalline lens. A teenager can typically accommodate as close as 3 inches. If the eyeball is elongated, the point of focus for distant objects would be in front of the retina. A concave lens can move the point of focus to the retina. The cornea also plays a part in focusing. In fact the cornea, according to sources, does two-thirds of the work, and if the cornea is too steep, can cause the image to focus in front of the retina as well. But how does the eye get elongated?

Most sources found will say that the primary reason is heredity and is more common in Caucasians and Asians. The number of people with myopia is said to be about one-third of the world's population. The source that I found and listed below says the cause stems from close work or using accommodation too much or without enough rest. A compelling argument and to me makes a lot of sense.

Here are a few excerpts from the article: "The abnormal elongation of the myopic eye. Our eyes were never designed by evolution for the way we use them today. In order for the eye to focus on close objects, the ciliary muscle tightens and causes the lens of the eye to thicken. Constant focusing on close objects causes a spasm of the ciliary muscle, a constant pulling on the sclera and a related pressure increase in the vitreous, or large chamber of the eye. As the sclera stretches and becomes larger, the body creates more liquid in the vitreous to fill the increased volume. This is the body's simple way of refining the vision by reducing the normal farsightedness of the infant. This natural elongation of the eye becomes abnormal when the eye has no farsightedness left and moves into a myopic condition."..."The lengthening of the eye that results from this stretching allows reading to be done with less focusing effort and is the body's way of relieving the stress of prolonged close work. Unfortunately, the eye is capable of continuing this lengthening process until it literally tears itself apart! By this is meant that the longer the eye becomes, the more likely it is for the retina to detach from the underlying tissues. This detachment can happen gradually or spontaneously. X-rays have shown that myopic eyes are stretched as much as 25% longer than normal. Pictures of such eyes are to be found in standard textbooks. Usually, such detachment eventually leads to blindness. Any overelongation of the eye can increase the risk of retinal detachment in later years." The research was done by Francis A. Young.

According to this research, prescribing a minus diopter allows better distance vision, but will also cause the eye to lengthen further.

Back in the seventies, I was an optician for 3 years, so I learned how to read a prescription, measure the distance between pupils so as to center the eyeglass correction, insert lenses into frames and adjust them to the patient as well as adjust misaligned frames from wear and accidents. I read about the anatomy of the eye and common malfunctions. Since then I work as a pilot and eyesight is very inportant in my line of work. Whenever I have encountered vision problems for myself or people I know, I have done further research to educate myself, as I have for your question.

Answer 6

I loved that you did this piece. I am inspired to write once again. I appreciate the significance of the rose that grew threw the concrete, reference. Nice touch. The third stanza was the best for me. Solid lines and visuals. All in all a great effort. Temari

Answer 7

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Answer 8

"Is it because of the lense inside my eye is defective??"

no

"or the muscles that adjust the lense have something wrong with them?"

no

"or my cornea is shaped different (too steep or whatever)?"

YES

"or is it because my eyeball is too long so the image is unable to focus on the retina?"

YES

"or could it be either of these or a combination..."

YES

so what is it..."primarily"? its PRIMARILY genetics. shape of your cornea (too steep) and axial length (size) of your eye.