Myopia: What is nearsightedness?

Are you able to see clearly when something or someone is near? Does your vision become blurry when you set your sights on distant objects or people? You may be suffering from myopia.

According to the American Academy of Ophthalmology (AAO), myopia, or more commonly known as nearsightedness, is a “refractive error.” This means that the eye “does not bend or refract light properly to a single focus”, preventing it from seeing distant images clearly. Therefore, it is an “eye focusing disorder,” and not a type of eye disease.

When our eyes focus on images, it relies on the cornea, the clear front surface of the eye, and the crystalline lens, a clear structure inside the eye that changes shape so we can focus on objects. Normally, these two parts have a smooth curvature that allows them to bend or refract incoming light.

Myopia happens when the eyeball is elongated or the cornea is too curved. When this happens, the light entering the eye is not focused clearly. Instead, the “light rays of images” focus in front of the retina, which is light-sensitive, rather than on the retina itself. This is what causes the blurred vision.

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Brief History

According to a myopia resource website, it was Greek philosopher and scientist Aristotle who first distinguished between myopia and hyperopia (or farsightedness). However, it was prominent Greek physician Galen who first used the word ‘myopia.’
The etymology of the word can be traced to the Greek words ‘myein’ which means ‘to close’ and ‘opos’ which refers to the eyes.

Thus, the word ‘myopos’ was used to describe a “condition in which an individual attempted to see clearly by partially closing the eyes,” also known as squinting. For people with myopia, squinting is a common manifestation of this eye condition because it aids in the attempt to see distant subjects.


Video Source: American Academy of Ophthalmology

Understanding Myopia

To better understand myopia, it is important to learn the basic definitions of some medical terms that you may hear from your doctor or read about when you conduct research.

Invisalens what is nearsightedness - better vision

REFRACTION: This refers to the bending of light as it passes through one object to another. Our vision occurs when light rays are refracted as they pass through the cornea and the lens. It is then focused on the retina, which then ‘converts’ these into messages sent through the optic nerve to the brain. The brain, of course, interprets these messages into the images that we see.

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REFRACTIVE ERRORS: Refractive errors happen when the shape of the eye makes it unable for the light rays to focus on the retina. An elongated eyeball or a change in the shape of the cornea, such as in the case of myopia, can cause refractive errors.

Causes and Stages of Myopia

The American Optometric Association (AOA) explains that while myopia is typically inherited, the actual development is triggered by how a person uses his or her eyes. People who often read (particularly under poorly lit settings), work in front of a computer, spend a lot of time in front of a screen, or do “intense close visual work,” are more prone to becoming nearsighted.

Myopia first develops during childhood but visual stress or aggravating health conditions, like diabetes, can worsen it during adulthood.

AOA identifies related problems such as:

1. Night Myopia: A case in which some people experience blurred vision only at night. This happens because the darkness makes it harder for the eyes to focus properly. Low light also tends to increase pupil size, thus allowing more unfocused light rays to enter the eye and affect the vision.

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2. Psuedo or Falso Myopia: A case in which people who do a lot of “near-vision work” find it difficult to “refocus to see clearly in the distance.” The temporary blur in vision is caused by “overuse of the eyes’ focusing mechanism.” Usually, clear distance vision is regained after resting the eyes (which is why it is important to regularly rest the eyes when working in front of the computer for long hours) but if this type of visual stress becomes regularly unchecked, it can eventually lead to permanent reduction in distance vision.

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Mild myopia is called low myopia, and conversely, severe myopia is known as high myopia. The latter is usually common among myopic people in their early adulthood—from age 20 to 30 years old. If continuously unchecked, people with high myopia have a higher risk of developing detached retina as well as glaucoma and cataracts.

Signs and Symptoms of Myopia

The most common manifestations of myopia includes:

  • Eye strain
  • Headaches
  • Squinting
  • Difficulty seeing distant objects (like road signs or billboards)

Among children, early signs of myopia can be spotted through these signs:

  • Needing to sit closer to the blackboard or to the TV screen
  • Holding books very close to the face while reading
  • Not being able to notice movement in distant objects
  • Blinking excessively
  • Rubbing the eyes frequently

It is crucial to immediately set an appointment with an eye doctor once these symptoms are detected.

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Early and proper intervention can help prevent myopia from getting worse, especially among children.

Diagnosing Myopia

Myopia is diagnosed through a comprehensive eye exam. If you are experiencing the aforementioned signs and symptoms, immediately visit your eye care professional for a nearsighted test.

A person’s myopia depends on the length of the eyeball, the steepness of the cornea and the lens inside the eye. To assess this, the eye doctor will likely use standardized procedures and tests to see how the eyes focus light and to determine the type of optical lenses needed to correct the vision impairment.

Part of the testing process will be to identify letters on a distance chart which measure visual acuity. The doctor will also likely use a phoropter—an instrument wherein a series of lenses are placed in front of the eyes.

The doctor will measure how the eyes focus light using a handheld lighting instrument called a retinoscope. In cases where in the patient cannot respond verbally, eye drops can also be used to temporarily keep the eyes from changing focus.

These tests will determine if a patient has myopia and at what stage it is. It will also provide information on the type and power of corrective lens needed to manage the symptoms and prevent it from worsening.

Alarming Statistics

In 2009, researchers found that 47 million Americans aged 20 and above are myopic. They also found that the prevalence increased by almost 42 percent from 1999 to 2004, a significant increase from 25 percent in the 1970s.

In Asia, a 2012 article on Time.com cited a study wherein researchers found that “up to 90% of young adults in major East Asian countries, including China, Taiwan, Japan, Singapore and South Korea, are nearsighted.” Although it has long been accepted that myopia is hereditary, the fact that in Singapore, for instance, the rate of myopia in three different ethnic groups have all increased and equally affected the population since 1996, suggests that there may be a shared environmental or behavioral factor.

Researchers are pinpointing “too much time indoors and not enough time outside in the sunlight” as the probable cause of the myopia epidemic in this part of the world.

Another article from Australia’s Sydney Morning Herald cited a study by the Brien Holden Vision Institute which predicts that 10 percent of the global population “will be at risk of blindness by 2050 if the prevalence of myopia continues to rise.

The article noted that, in China, 81 percent of teenagers are nearsighted, and institutions are heeding the warning signs. In one Chinese school, doors are locked for two hours a day, barring the children from going inside so they can enjoy and benefit from the natural eye care properties of sunlight. Meanwhile, in Taiwan, approximately 95 percent of students require corrective glasses for myopia and parents can be fined for allowing their children to go overboard on digital devices because it is considered a form of child abuse.

The myopia problem is not just happening in schools. In South Korea, a study of 24,000 army recruits revealed that 97 percent are nearsighted, with 22 percent suffering from high myopia.

Myopia Among Children

Among Asian school children, approximately 10 to 20 percent have high myopia. This can put them at higher risk of more serious eye problems, even blindness, as they grow older. The same Time article pointed out that this alarming phenomenon can be attributed to the “massive pressure” on Asian children to excel academically, which in turn leads to long hours hunched over books with little to no time for natural sunlight. In fact, in East Asian countries, high myopia rates are seen among those who rank highest in academic performance.

Behavioral and environmental factors may trigger myopia among children but medical experts agree that it is an inherited condition. If one or both parents are myopic, the likelihood that their children will develop myopia also increases. Nearsightedness in children often begins between ages eight to 12, and can worsen as they go through their teenage years.

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Complications

If left unchecked, nearsightedness can progress into more serious vision problems and can permanently affect a person’s quality of life.

Uncorrected myopia can cause severe eye strain and headaches because of the constant squinting and straining to maintain focus. It can also impair the safety of the patient and those around him/her.

  • Posterior vitreous detachment (PVD): PVD happens because of the  natural changes in vitreous—the ‘jelly’ in the eye. It can develop  earlier among myopic people.
  • Retinal detachment: Because of retinal elongation, a hole or tear  can develop and the fluid in  the eyes can leak behind the retina.  This can cause the retina to detach from the back of the eye.  Consult  your doctor if you see a ‘curtain effect’ coming up, down or  across  your line of vision.
  • Glaucoma: Glaucoma is the second leading cause of blindness,  according to the Glaucoma Research Foundation. It is a  “complicated  disease” which is caused by damaged optic nerves. It  can lead to “progressive and irreversible” loss of vision. Cataract: It  is the clouding of the eye’s natural lens, located behind the iris and  the pupil.
  • Cataract: is the most common cause of blindness in the world.

  • Retinal atrophy: As the retina stretches, it becomes thinner  and this can affect the retinal cells. This can cause impaired  vision in the areas of atrophy.
  • Lattice degeneration: Lattice degeneration happens when  thinning develops at the edge of the retina. It can increase  the risk of retinal detachment.
  • Lacquer cracks: Lacquer cracks are the fine lines or breaks  that appear on the retina as a result of the eye stretching.
  • Development of new vessels: This is known as choroidal  neovascularisation (CNV). This happens when new blood  vessels grow from the blood supply under the retina.  Because they are weak and fragile, these blood vessels can  bleed easily and cause damage and swelling to the retina. If  the new blood vessels develop at the central part of the  retina (called myopic maculopathy), it can affect the central  and color vision, making it difficult to see people’s faces  and distorting straight lines.

Treatment

The goal of treating myopia is to improve vision, particularly distance vision, by helping focus light on the retina.

Online medical resource site Mayo Clinic identifies refractive surgery and corrective lenses as two options for nearsighted people.

Refractive Surgery

The goal of treating myopia is to improve vision, particularly distance vision, by helping focus light on the retina.

Online medical resource site Mayo Clinic identifies refractive surgery and corrective lenses as two options for nearsighted people.

The common types of refractive surgery are:

  • LASIK: During LASIK, the surgeon makes a thin, hinged flap on the  cornea and uses an excimer laser, which doesn’t produce heat, to  flatten its domed shape. After this, the thin flap on the cornea is  repositioned.
  • LASEK: In LASEK, the surgeon creates a flap in the epithelium, the  thin protective cover of the cornea, and then uses the excimer laser  to reshape the outer layers of the cornea and flatten the curvature.  Post-LASEK, patients usually wear bandage contact lens to aid in the  healing process.

  • PRK: Photorefractive keratectomy is a lot like LASEK except  in this type of surgery, the surgeon removes the  epithelium. The epithelium naturally grows back,  conforming to the new shape of the cornea.
  • Intraocular (IOL) implant: Lenses are surgically implanted  in front of the eye’s natural lens. This type of surgery is  recommended for people with moderate to severe myopia,  although this is not considered a mainstream option.

It is important to note that refractive surgery, like any type of surgery, can come with possible complications such as: 

  • Under or overcorrection of the original vision problem
  • Visual effects such as seeing a halo or a starburst around lights
  • Dry eyes

  • Infection
  • Corneal scarring
  • Vision loss in rare or extreme cases

Corrective Lens

The goal of wearing corrective lens, either through glasses or contact lenses, is to counteract the increased curvature of the cornea or the increased length of the eye.

Eyeglasses are the simplest, most common and safest way to manage myopia. It is important to wear properly graded eyeglasses because otherwise, vision problems can worsen.

Meanwhile, contact lenses come in different types—hard, soft, extended wear, disposable, rigid gas permeable, and bifocal. There are also custom designed molding lens which allow wearers to see more clearly after wearing it overnight. This process is called orthokeratology, also known as ortho-k.

As in all treatment options, it is always best to consult with a certified eye doctor for the right type of corrective lens.

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Eye Drops

The Singapore National Eye Centre (SNEC) website noted that, for childhood myopia, low dose atropine is effective in slowing down the progression, with little to no side effects, by 50 to 60 percent over a two-year period. Topical atropine is used to dilate the pupil and relax the eyes’ focusing mechanism.

It also noted that low-dose atropine is safer and more comfortable than its higher-dose version.

For those suffering from stress-related myopia, vision therapy is an option to control the muscle spasms that affect the focusing mechanism of the eyes. Professionally guided eye exercises can help improve the eye’s focusing ability particularly for distance vision.

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Eye Care Tips

To help mitigate the vision problems caused by myopia, it is also worthwhile to follow these simple and yet oft ignored eye, and general health, care habits.

  • When reading, make sure the material is at least 30 centimeters  away from the face or the eyes. Avoid reading while lying down, and  make sure that there is sufficient lighting.
  • When watching television, make sure to be at least two meters  away from the screen.
  • When using the computer, make sure to be at least 50 centimeters  away. Do not forget to adjust the screen settings and minimize the  glare.
  • Limit screen time and spend more time outdoors; indirect natural  light is good for the eyes.
  • Manage chronic health conditions such as high blood pressure and  diabetes because these can affect vision if proper treatment is not  received and maintained.

  • Protect eyes from harmful ultraviolet rays, and make a  conscious effort to prevent eye injuries especially when  playing sports or doing activities that expose your eyes to  harmful fumes and chemicals.
  • Take regular breaks when reading, watching TV and  especially when using the computer. Look out the window  at distant objects or close your eyes to relax.
  • Live healthy. Eat fruits, leafy greens and other vegetables.  Avoid smoking if you can.
  • Make eye check-ups a part of your regular or annual health  checks.

Aside from treatment, experts suggest that children with myopia should not be made to feel as though they have ‘bad eyes.’ It is important to make them understand their condition and reiterate that it can be managed. Their regular activities should not be restricted and they should be encouraged to talk about their vision so they can be actively part of the solution and the treatment process.

Facts and Myths

  • MYTH: Reading or pinhole glasses can prevent myopia.

  • FACT: There is no research that supports the fact that  reading or pinhole glasses are effective for all myopic  people. It is still best to consult with a professional for  effective ways of managing myopia.


  • MYTH: Weaker glasses will make eyes work harder and wearing  glasses can make myopia worse.

  • FACT: Wearing the correct glasses can, in fact, help provide  clear distance vision and this does not worsen myopia.  Wearing weaker glasses, on the other hand, can aggravate  vision problems in the long run.

  • MYTH: Myopia can be controlled because it develops based on how  we use our eyes.

  • FACT: The exact cause of myopia is unknown but experts  agree that myopia develops from a combination of genetics  and environment.

  • MYTH: All types of contact lens can prevent or slow progression of  myopia.

  • FACT: It is best to consult with your doctor about the kind  of lens that is specifically helpful for nearsighted people.  Currently, there are special types of lens that can help  manage myopia.

Living with Myopia

For nearsighted people, eyeglasses or contact lenses are constant, crucial and inescapable parts of their day-to-day activities—whether it is driving, meeting with people, walking or watching a movie. For those who read or work in front of the computers for most of the day, glasses are more ideal because it can be easily removed.

With today’s advancements in medical technology, people with myopia now have more options for longer lasting treatment, since corrective lens cannot arrest the progression of nearsightedness. Read up, research and ask experts so you can get started on your journey towards normal and clear distance vision.

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