Myopia, or nearsightedness, is a vision condition where distant objects appear blurry, while close-up objects remain clear. Light entering the eye focuses in front of the retina, rather than directly on it. This widespread condition affects about one-third of children and adolescents globally, with projections indicating it could affect nearly 5 billion people by 2050. Its prevalence continues to rise, making it a common refractive error.
Understanding Myopia’s Development
Myopia develops due to changes in the eye’s physical structure. An elongated eyeball, where the distance from front to back is too long, is the most common reason. A steeply curved cornea, causing excessive light bending, can also contribute. These alterations prevent light from focusing precisely on the retina, resulting in blurred distant vision.
Once these structural changes occur, they are considered permanent. The eye’s physical dimensions, once myopic, tend to remain that way. Myopia does not resolve naturally over time without intervention.
Myopia often begins in childhood, progressing through adolescence as the eye grows. It can stabilize in early adulthood, usually between ages 20 and 30, but the structural changes persist.
Genetic predisposition plays a role, as children with myopic parents are more likely to develop the condition. Environmental factors also contribute, including prolonged near-work activities like reading or digital device use, and insufficient time outdoors.
Managing Myopia
Corrective lenses, such as eyeglasses and contact lenses, manage myopia by altering light’s path to focus correctly on the retina. These optical aids restore clear distant vision.
While corrective lenses provide clear vision, they manage symptoms rather than altering the underlying eye structure. They do not prevent further eye elongation or correct existing anatomical changes. These lenses are a compensatory solution, allowing clear vision while living with the condition.
Beyond standard correction, strategies focus on slowing myopia progression, especially in children. Low-dose atropine eye drops (0.01% to 0.05%) reduce myopic progression. Orthokeratology (Ortho-K) involves wearing rigid contact lenses overnight to temporarily reshape the cornea, managing progression during the day.
Specialized multifocal contact lenses and eyeglasses for myopia control provide clear central vision while defocusing peripheral light, inhibiting excessive eye growth. Lifestyle adjustments also help manage progression, including increasing outdoor time (90 minutes to 2 hours daily) and reducing prolonged near-focused activities.
Permanent Vision Correction
For adults with stable myopia, refractive surgery can reduce or eliminate the need for corrective lenses. These procedures permanently alter the eye’s structure to improve light focus on the retina. While they correct vision, they compensate for the underlying condition rather than curing it.
LASIK (Laser-Assisted In Situ Keratomileusis) reshapes the cornea with a laser. A thin flap is created, lifted, and laser energy removes microscopic tissue underneath. The flap is then repositioned, improving light focusing.
PRK (Photorefractive Keratectomy) also reshapes the cornea with a laser. Unlike LASIK, PRK removes the outer corneal layer before reshaping the underlying tissue. This layer regenerates naturally over a few days. Both procedures flatten corneal curvature, allowing light to focus more accurately on the retina.
For those unsuitable for laser vision correction due to factors like thin corneas or high prescriptions, Implantable Collamer Lenses (ICL) are an alternative. An ICL is a thin, flexible lens surgically implanted inside the eye, typically between the iris and natural lens, providing permanent vision correction. Eligibility depends on age, refractive stability, and overall eye health.