Nearsightedness (Myopia): Symptoms, Causes & Treatment

Myopia is a visual disorder in which the affected person can clearly see objects that are closer to them but has difficulty seeing objects that are further away, thus the term nearsightedness.

This condition has a familial link in many instances. It can either appear gradually or progress rapidly.

Over a quarter of the entire global population suffers from a form of myopia. Projections indicate that by 2050, almost half of the entire world population will be affected.

Myopia is classified into two forms: high myopia and pathological myopia. Pathological myopia appears gradually, initially starting in childhood and potentially morphing into a serious form in adulthood and old age.

High myopia has a more rapid onset. It usually results in other serious forms of visual disorders that include cataracts, glaucoma or even retinal detachment.

Causes & Risk Factors for Myopia

Physiologically, there are instances where the eyeball is longer in relation to the focusing power of the cornea and the lens. This physiological condition results in the distortion of the light rays entering the eye.

In myopia, the light rays that normally would have rested on the surface of the retina focus on a point beyond the retina.

Myopia can also result when either the cornea or the lens of the eye are extremely curved beyond the length of the eyeball. In some instances, myopia may be due to distortions in both the cornea and the lens.

Several factors might predispose you to develop nearsightedness. Below are risk factors for myopia: 

• Genetics: Numerous studies show that there is a link between myopia and genetics. If one parent has nearsightedness, the child is 1.5 times more likely to also have it. If both parents have myopia, the child is 3 times more likely to also develop it. This high incidence rate shows just how much genetics play into a predisposition for nearsightedness.
• Habits: Lifestyle factors, like spending too much time in front of the television screens, computers, or phones is a major factor for myopia. Excessive screen time may stimulate nearsightedness, leading to its gradual or, in some instances, rapid progression.
• General health: There are some diseases that are risk factors for myopia. Diabetes is strongly linked to myopia.
• Age: Children, especially those younger than 12, who develop myopia have shown a rapid progression of the disease compared to their peers in older age groups. The formative years in a child’s life involve rapid growth of their organs, including their eyes. Instances where the eyes are affected might also result in rapid degeneration like instances of nearsightedness.
• Geographical predisposition: People in urban areas tend to spend less time outdoors compared to people from the rural areas. Exposure to outdoor spaces and more sunlight is linked to fewer incidences of myopia, meaning those in the rural areas are less likely to be affected by myopia compared to those in urban areas.

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Symptoms of Nearsightedness

In most cases, nearsightedness is diagnosed in childhood, but it may also be diagnosed in adulthood. The general symptoms of myopia include the following:

• Straining the eyes, causing incessant headaches
• Difficulty operating machines, including trouble driving, especially in the dark
• Faraway objects appearing blurry
• Squinting the eyes when trying to focus on an object

A study carried out by Children’s Hospital of Pittsburgh found that there are certain symptoms to look out for in children that might indicate they are suffering from a form of myopia.

• The child opts to sit in the front of the classroom to be able to clearly see the board.
• The child moves a tablet or phone closer, or sits closer to the television set, to be able to watch something. 
• The child might be disinterested in sports or activities that require high visual acuity and focus to excel.
• The child holds a book closer to their face to be able to read.
• The child continually squints their eyes, which might also include frowning, as they try to focus on objects.

Diagnosis

For best correction and management, myopia should be diagnosed in its early stages.
It can be easily diagnosed by an eye doctor.

There are several types of eye tests, which a doctor will use to assess if you have nearsightedness. Different tests are used for adults and children.

The first in a series of tests is the measure of visual acuity, using the standard reading chart, also referred to as the Snellen test.

For adults, a doctor uses a lighted retinoscope to assess how the eyes respond to light. This assessment will guide the doctor in diagnosing myopia.

Children should have regular eye exams, with the first one occurring by the time they are 1. Regular checkups are particularly important for children predisposed to nearsightedness due to their parents having it.

The exams change as the child grows. When children are very young, doctors use special devices, such as vision screeners or autorefractors, to detect vision abnormalities. As they get older and can identify pictures and letters, they will progress to using eye charts to test visual acuity.

Treatment & Management of Myopia

While myopia can significantly limit vision, there are many treatment options available.

• Glasses: Eyeglasses are the most common treatment to manage myopia. The right lenses ensure that the light entering the eyes settles on the right spot on the retina, allowing objects to properly come into focus. Depending on the severity of nearsightedness, you may need to wear glasses for certain activities or all the time.
• Contact lenses: As another form of corrective lenses, contact lenses function just like glasses. Since contact lenses rest directly on the eyeball, you may enjoy more flexibility and freedom with contacts; however, some people find contacts uncomfortable.
  
  Some people experience better vision correction with contact lenses versus glasses. It’s a matter of determining which works for your situation.
• Laser surgery: LASIK, or laser-assisted in situ keratosis, is the primary surgical procedure used to correct nearsightedness. The procedure is simple and straightforward, and boasts high success rates.
  
  Lens implant surgery is another surgical approach to correcting myopia. This surgery is usually reserved for those with severe forms of myopia who are not candidates for LASIK. Specialized lenses are implanted into the eyes to correct vision.
• Medication: Doctors sometimes prescribe atropine eye drops to slow the progression of myopia in children. While children will still develop myopia, studies have shown it isn’t nearly as severe when low-dose atropine drops are used at bedtime.

Nearsightedness Prevention

Research reported in Investigative Ophthalmology and Visual Science shows that the progression of nearsightedness can be delayed and even potentially prevented. These are some of the approaches used to decrease the likelihood of myopia:

• Spend more time outdoors. Exposure to sunlight has been linked to slower progression of myopia, particularly in children. At least two hours of outdoor activity that includes exposure to sunlight is recommended to slow or even prevent the development of nearsightedness.
• Manage underlying health conditions. Diabetes increases the likelihood of developing myopia. Keep diabetes under control to reduce this risk.
  
  Some other conditions, such as Marfan syndrome, increase the likelihood of co-occurring myopia. Talk to your doctor about how best to manage these risks.
• Get regular eye exams. Myopia is best managed when diagnosed early before it progresses too much. Annual eye exams can detect myopia in its early stages. 

Myopia Complication

Late diagnosis or lack of treatment of myopia can result in serious complications, some of which cannot be reversed. Potential complications of myopia include the following:

• Glaucoma: People with high levels of myopia have an increased risk for glaucoma, which is increased fluid pressure in the eye. If left untreated, this can lead to severe vision loss, including blindness.
• Macular degeneration: Myopia may result in an increase in axial elongation, which can lead to macular degeneration. When this occurs, it is called myopic macular degeneration. It is a severe and rare form of myopia.
• Cataracts: People with myopia have an increased likelihood of developing cataracts, which refers to clouding of the eye’s lens.
• Myopic traction maculopathy: This can occur in those with high myopia. It involves a thickening of the retina, straining the inner layers of the eyes, which are gradually impaired.
• Blindness: If complications of myopia are untreated, they may progress to blindness. In many instances, this vision loss is irreversible.

Although genetics play a huge role in your predisposition to nearsightedness, you can take steps to slow its progression and decrease the likelihood of severe issues. Maintain your eye health, and your overall health, with regular eye exams and a healthy lifestyle. 

References

1. The Science Behind Myopia. (November 2017). Webvision: The Organization of the Retina and Visual System.

2. Half the World Short Sighted by 2050. (February 2016). Brien Holden Foundation.

3. Myopia: Risk Factors, Disease Mechanisms, Diagnostic Modalities, and Therapeutic Options. (June 2018). Journal of Ophthalmology.

4. Prevention of Progression in Myopia. (Dec 2018). U.S. National Library of Medicine.

5. Treatment Options for Myopia. (June 2009). U.S. National Library of Medicine.

6. Comparison of Contact Lens Corrected Quality of Vision and Life of Keratoconus and Myopic Patients. (December 2017). Korean Journal of Ophthalmology.

7. Environment, Genetics & Myopia – COPE 2 Hours. (March 2019). Review of Optometry.

8. Treatment Shortsightedness. NHS.

9. Myopia Nearsightedness. Cleveland Clinic.

10. Illustration of an IOL in place in the eye Phakic Intraocular Lenses for Nearsightedness. (February 2017). American Academy of Ophthalmology.

11. Low-Dose Atropine for Kids With Myopia. (August 2017). American Academy of Ophthalmology.

12. Sunlight Exposure Reduces Myopia in Children. (August 2018). American Academy of Ophthalmology.

13. Myopia, Pathological Myopia and Myopic Macular Degeneration. Macular Society.

14. Myopia, Axial Length, and Age-Related Cataract: The Singapore Malay Eye Study. (July 2013). Investigative Ophthalmology and Visual Science.