Myopia: Causes, Symptoms, and Treatment for Nearsightedness

What Is Myopia (Nearsightedness)?

Myopia, commonly called nearsightedness, is a refractive error in which close objects appear clear while distant objects appear blurry. It is the most common refractive error worldwide, affecting approximately 2.6 billion people globally as of 2025 — about 30% of the world's population. The term "myopia" derives from the Greek for "to close the eyes" or "squint," reflecting the tendency of myopic individuals to squint when trying to see distant objects clearly.

Causes: Axial Length and Corneal Curvature

Myopia occurs when the eye's optical power is too strong for its axial length (front-to-back diameter) — causing light to focus in front of the retina rather than directly on it. This can result from:

• Axial myopia (most common): the eyeball is too long; for every millimeter of additional axial length, approximately 3 diopters of myopia are added
• Refractive myopia: the cornea or lens is too steeply curved, creating excessive optical power even with normal axial length

Genetic factors are the strongest determinants of myopia — children with two myopic parents have a 50–60% chance of developing myopia. Environmental factors also play a significant role: insufficient time outdoors and extensive near work are both associated with myopia development and progression, particularly in urban East Asian populations. See eye anatomy for how axial length relates to refractive power.

Symptoms of Myopia

Classic symptoms of myopia include: blurry vision when looking at distant objects (road signs, whiteboards, sports in the distance); squinting to improve clarity; eye strain and headaches after prolonged distance viewing; difficulty seeing clearly while driving, especially at night; and needing to sit closer to screens or boards to see clearly. Myopia typically becomes symptomatic in school-age children, when they struggle to see the classroom board from their seat.

The Global Myopia Epidemic

Myopia prevalence has increased dramatically over the past 50 years, particularly in East Asian countries where rates exceed 80% among young adults in urban areas. The World Health Organization projects that by 2050, approximately 50% of the global population — 4.8 billion people — will be myopic. High myopia (over -6 D) is associated with elevated risks of retinal detachment, glaucoma, myopic macular degeneration, and other serious eye conditions. This public health concern has driven significant investment in myopia control interventions.

Myopia Progression: When Does It Stabilize?

Myopia typically begins in childhood between ages 6 and 14 and progresses through adolescence. Most people stabilize their prescription by age 20–25, though some individuals continue progressing into their late 20s. Rate of progression varies widely — some children progress rapidly (1+ D per year); others progress slowly. Myopia control strategies aim to slow progression during the developmental years. For LASIK purposes, stable prescription (no more than 0.50 D change in 12 months) is required. See LASIK age requirements.

Treatment Options for Myopia

Treatment	Corrects Myopia?	Controls Progression?	Permanent?
Glasses	Yes	No	No
Soft contact lenses	Yes	No	No
Orthokeratology (Ortho-K)	Yes (temporary)	Yes (moderate)	No
Atropine drops (low-dose)	No	Yes (significant)	No
Multifocal contact lenses	Yes	Yes (moderate)	No
LASIK / PRK / SMILE	Yes	N/A (adult only)	Yes (corneal)
ICL	Yes	N/A (adult only)	Reversible

LASIK for Myopia: The Most Effective Adult Correction

For adults with stable myopia, LASIK is the most effective and permanent correction option. The excimer laser flattens the central cornea, reducing its refractive power to compensate for the excessive power causing myopia. LASIK can treat myopia up to -12 D (optimal range up to -8 D). See LASIK prescription limits. For patients with high myopia beyond LASIK's range or insufficient corneal thickness, ICL surgery is the preferred alternative. Over 96% of myopic patients who undergo LASIK achieve 20/20 or better vision. See LASIK results.