Myopia is the most common type of refractive errors worldwide. Also, the cause for which most patients visit eye care doctors is myopia. It is the most common cause of wearing glasses, contact lenses and refractive (laser) surgeries.
We will help you to understand more about Myopia in simple words.
Myopia is a refractive error that existed in people eyes before anyone call it “myopia” or “nearsightedness”. I want you to understand that “myopia” and “nearsightedness” are just terms given to an existed eye condition. So, don’t be stuck with the explanation of the terms when trying to understand the definition and meaning of myopia. It is better to understand the condition as the first scientists who discovered it rather than trying to define “myopia” as it is a linguistic term.
How did scientists discover myopia?
Scientists found that some people don’t see as clear as normal people.
Then, scientists looked for the cause that makes these people see blurred images. They found that the eyes of people having myopia don’t focus the images of objects on the retina (like normal people eyes do), but somewhere in front of the retina and this makes far objects look blurry to them.
The scientists looked up the dictionary to find one term which could fully and clearly describe this condition, they found the term “myopia”. Actually “myopia” is a Greek term still used until nowadays. Myopia is also known by the public as “nearsightedness”. Nearsightedness doesn’t imply the condition as it is really is. It is true that people with myopia suffers more at far distance vision, but this doesn’t mean that they have no problems at near vision.
That’s why I always confirm that we shouldn’t be stuck with the terms’ explanations to understand the conditions as we are not going to define one on a linguistic basis.
So, normal people eyes focus the images on the retina, while myopic eyes focus images in front of the retina.
The further the images are focused in front of your retina, the more amount of myopia you have.
What are myopia Causes?
To explain the causes of myopia very simply, let us talk more about the eye and the mechanism of focusing images in the eye.
The eye is having the shape of the ball and the retina (where the images are supposed to be focused on) lies on the back of this ball. The other eye structures are required to focus images on the retina in order to see clearly. This mission is done basically by two structures which are the cornea and the lens of the eye.
These two structures have the ability (power) to focus images of objects.
In the normal eye, the distance from the front of the eye ( the cornea) to the retina is 24 mm. The sum of the powers of the cornea and the lens is 62 Dioptre ( unit of lens powers).
So, 62 Dioptre power focuses images on 24 mm distance, but if the power of the cornea and lens is more than 62 D, this means that the focus of the images will be in front of the retina at ( 22 mm distance, for example, or less instead of 24 mm) and this will make you see blurred images.
On the other hand, if the power of the cornea and lens is normal (62 D), but the distance from the eye’s front to the retina is more than 24 mm (26 mm or more for example), this means that the focus of the images will be in front of the retina ( at 24 mm as power is 62 D).
So shortly, the myopia causes are:
1- High power of the eye’s optical system ( cornea or lens or both two).
2- The eye length is longer than normal, that’s they have a longer distance from the front of the eye ( the cornea) to the back of the eye ( the retina).
Now, the questions are what are the causes that make the myopic eyes are more powerful than normal eyes? And also what are the causes that make the myopic eyes longer than normal eyes?
The answers of these questions are still not clear and no research or study found out the specific cause yet, but scientists believe that there are factors that contribute to myopia development which are :
1- Genetic factors: including ethnicity and family inheritance.
2- Environmental factors.
3- Excessive near work: many eye care experts think that excessive near work has a role in the development of myopia and its increase. Although, no study restricted with research methodology conditions has proved this yet.
Myopia symptoms manifested as either blurred vision or eye fatigue. These symptoms, as well as photophobia produced by the dilated pupil are usually secondary to the difficulties at the far distance vision.
Also, The blur when reading results when the print is held at a reading distance that is farther than the patient’s far point.
The patient must hold or move the reading material closer to secure clarity.
Reading, while uncorrected, at this near point may lead to eye fatigue and photophobia.
From my clinic experience, many questions are asked by patients after diagnosing them “or their children” with myopia. The most common question is “what is myopia cure?”. This question is asked spontaneously and unconsciously.
It is very normal that the person is looking for “a cure” that heals his condition and nothing wrong with that. But, guess what? If the patient is not going to consider eyeglasses or reusable and comfortable contact lenses as “myopia cure”, then the answer to his question is “No sir, there is no “cure” for myopia.
To go deep in the patient questioning, some patients ask the question in other forms which is “Will glasses cure my myopia?”
To answer this question, doctors and specialists think in a scientific manner. For glasses to cure myopia, it must remove the causes of that myopia. As we talked above, the causes of myopia include abnormal cornea or lens curvature and increased eye length than normal. Glasses have nothing to do with the curvature of the cornea or lens and don’t shorten your eye length. So, glasses don’t remove the cause of myopia and surely will not remove or “cure” myopia.
Even laser eye surgery doesn’t remove the cause of myopia. The laser eye surgery works only on the cornea, while the cause may be the lens of the eye or the eye length. Even if the cause is only the cornea, the laser eye surgery must do two things to be considered as “myopia cure”. The first thing is to correct the curvature of the cornea, and that what does it do?. The second thing is to stop any future abnormal change in the corneal curvature. And this is what it couldn’t do.
The above two paragraphs might be a key answer to many other patients questions coming in the same area of the cure or treatment of myopia and other refractive errors. Think of the answer to any questions in your mind about “myopia cure” by the same ideas mentioned in the above two paragraphs, and surely you will get the convincing answer.
So until nowadays, we don’t have any cure for myopia. We just have “myopia treatment”. There are many alternatives for the treatment of myopia which are :
1- Eyeglasses: your optometrist or ophthalmologist will prescribe you eyeglasses to correct your myopia, with the specific number of lens power. This power of the lens will move the image in your eye from in front of your retina back to your retina. This will enable you to see clearly as normal people do.
2- Contact lenses: have the same idea as the spectacle lenses. Contact lenses correct your myopia by resting on your cornea. Contact lenses are more preferable and have many advantages over wearing glasses such as:
a- Cosmetic reasons: Not everyone can get used to wearing glasses and how they look when wearing ones. On the other hand, wearing contact lenses are perfect for people who want to subtly enhance the color of their eyes.
FreshLook Colorblends contact lenses are perfect for the contact lens wearer looking to subtly enhance their eye color.
b- Advantages from optical reasons: The quality of images reach the retina is better in contact lenses than in glasses specially in high myopic people ( over 6 Dioptres of myopia).
3- Orthokeratology: This is an alternative way of correcting myopia by rigid contact lenses, but with a different idea. The idea here is to wear specially designed rigid contact lenses while you are sleeping and these contact lenses will work on reducing the power of your cornea by changing its curvature all overnight. When you wake up in the morning, immediately remove the lenses and you will see things better.
4- Surgery to correct the refractive errors: This alternative treatment is allowing you in having clear vision without the need of wearing contact lenses or glasses. The most commonly used procedures nowadays are:
a- PRK (photorefractive keratectomy): this procedure consists of reshaping the cornea by the surgeon, by applying the laser directly on the cornea’s surface. This corneal reshaping is reducing the cornea’s power and is making the light rays of images focusing on the retina.
b- Lasik: This procedure consists of making a flap by the surgeon in the outer cornea and applying the laser pulses on the middle tissues of the cornea to correyopia.
c- ICL (implantable Collamer lens): This procedure is new and invented as a good solution for those who don’t fit the requirements of Laser surgery. A Collamer lens that is implanted is correcting your eye myopia in this procedure.