Myopia

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Myopia, also known as Nearsightedness, is a common eye condition in which close objects are seen clearly but distant objects appear blurry. It is characterized by the eyeball being too long or the cornea being too steep, causing light to focus in front of the retina instead of directly on it.

Etymology

The term “Myopia” comes from the Greek words “miosis,” meaning constriction, and “opsis,” meaning sight. This refers to the fact that people with Myopia often have difficulty seeing distant objects clearly due to their eyes being shorter than normal.

Causes

Myopia is caused by an abnormal shape of the eyeball or cornea, which affects how light enters the eye. The most common cause of Myopia is a family history, but it can also be caused by other factors such as:

  • Genetics: Myopia tends to run in families, suggesting a genetic component.
  • Near work: Performing near tasks for extended periods can lead to Myopia.
  • Age: Myopia typically develops in children and adolescents, with symptoms often appearing between the ages of 5 and 15.

Symptoms

People with Myopia may experience:

  • Close objects appear blurry or fuzzy
  • Distanced objects appear clear
  • Difficulty seeing distant objects clearly
  • Headaches or eye strain from focusing on close objects
  • Squinting to see distant objects

Diagnosis

Diagnosing Myopia typically involves a comprehensive eye exam, including:

  • Ophthalmoscopy: A special lens is used to examine the retina and optic nerve.
  • Refraction test: The eyes are tested for their ability to focus light correctly on the retina.
  • Retinoscopy: A tool is used to measure the curvature of the cornea.

Treatment

Treatment options for Myopia include:

  • Glasses or contact lenses: Correcting Nearsightedness with Glasses or contact lenses that focus light properly on the retina.
  • Refractive surgery: Surgical procedures such as LASIK, PRK, or LASEK can correct Nearsightedness by reshaping the cornea.
  • Orthokeratology (OK): A non-surgical procedure where a specialized contact lens is worn while sleeping to reshape the cornea.

Complications

If left untreated, Myopia can lead to:

  • Presbyopia: Age-related loss of near vision due to a decrease in lens flexibility.
  • Myopic shift: Gradual worsening of Myopia over time, which can cause Distance vision to decline more rapidly than near vision.
  • Glaucoma: Increased pressure in the eye can damage the optic nerve and lead to vision loss.

Prevalence

Myopia is estimated to affect around 34% of children worldwide and up to 50% of adults. It is a leading cause of Vision impairment and can have significant impacts on daily life, relationships, and productivity.

Statistics

  • Global prevalence: Estimated at 34% in childhood and 52% in adulthood.
  • Countries with highest prevalence:
    • China: 44%
    • United States: 38%
    • India: 35%
  • Age of onset: Most common in children between 5-15 years old.

References

  • American Academy of Ophthalmology. (2020). Myopia.
  • National Eye Institute. (2020). Myopia.
  • World Health Organization. (2019). IBDG: Nearsightedness.