Myopia, commonly known as nearsightedness, is a widespread vision condition where objects up close appear clear, but distant objects are blurry and out of focus. This happens because the eye is not correctly bending, or refracting, light to focus precisely on the retina, the light-sensitive tissue at the back of the eye. This article will explore whether this common refractive error is temporary or permanent and detail the methods used to manage and correct the condition.
The Permanence of Myopia
True myopia generally does not disappear once it has developed, primarily because it is caused by a permanent structural change in the eye. The most common form, axial myopia, occurs when the eyeball elongates and becomes too long from front to back, causing light to focus in front of the retina instead of directly on it. This structural lengthening, especially when it occurs during childhood, is not reversible and typically stabilizes only in early adulthood, around the early 20s, when the eye stops growing.
Myopia is distinct from a temporary condition known as pseudomyopia, or false myopia, which can resolve. Pseudomyopia is caused by a spasm of the ciliary muscle, the muscle responsible for focusing the eye, usually after prolonged, intense near work like reading or using screens. This muscle spasm temporarily prevents the eye from relaxing its focus for distance vision, mimicking true myopia. A simple test using special eye drops to relax the focusing muscle can differentiate this temporary condition from the permanent structural changes of true myopia.
Once true myopia is established, the eye has permanently surpassed the natural developmental process called emmetropization. The elongation of the eye associated with myopia is particularly concerning when it leads to high myopia, which is a prescription greater than -6.00 Diopters. This stretching of the eyeball can thin the retina and increase the risk of serious eye diseases later in life, such as retinal detachment, glaucoma, and myopic maculopathy.
Standard Vision Correction Methods
Correcting blurry vision is the primary goal once myopia is confirmed, achieved by refocusing light onto the retina. The most common method involves prescription eyeglasses, which use minus lenses to effectively reduce the eye’s overall focusing power and achieve clear distance vision.
Contact lenses, both soft and rigid gas-permeable (RGP), offer an alternative form of correction that sits directly on the eye’s surface. Soft contact lenses are comfortable and flexible, while RGP lenses provide crisp vision and can correct higher degrees of astigmatism. Both contact lenses and eyeglasses compensate for the eye’s shape error, allowing light to focus correctly, but they do not alter the underlying permanent structure of the eyeball or stop the progression of the condition.
For adults whose myopia has stabilized, refractive surgery offers a longer-term solution to reduce or eliminate the need for corrective lenses. Procedures like Laser-Assisted In Situ Keratomileusis (LASIK) and Photorefractive Keratectomy (PRK) reshape the cornea to adjust how light is focused. While these procedures correct blurry vision, they do not change the fact that the eye is structurally elongated or eliminate the potential health risks associated with high myopia.
Strategies to Slow Myopia Progression
While existing myopia is permanent, specific treatment strategies are available to slow down its progression, especially in children and adolescents whose eyes are still developing. The goal of these interventions, known as myopia control, is to minimize the continued lengthening of the eyeball, thereby reducing the final prescription and the associated risks of eye disease.
One pharmaceutical treatment involves the use of low-dose Atropine eye drops, typically at a concentration of 0.01% to 0.05%. These drops are administered daily and have been shown to effectively slow down the eye’s elongation. Though the exact mechanism is not fully understood, it is believed to involve a direct effect on the sclera, the white outer layer of the eye, to inhibit growth.
Specialized optical treatments are also highly effective in controlling progression. Orthokeratology, or Ortho-K, uses custom-designed rigid contact lenses worn overnight to temporarily and gently reshape the cornea. This process flattens the center of the cornea and alters how light is focused on the peripheral retina, which sends a signal to the eye to slow its growth.
Other optical methods include specialized soft multifocal contact lenses and specific designs of spectacle lenses. These lenses work by creating a clear focus in the center of the visual field while intentionally introducing a controlled amount of blur, or myopic defocus, in the peripheral vision. This peripheral defocus is thought to reduce the signal that drives the eye to elongate.
Lifestyle adjustments are also an important part of a comprehensive management plan. Increasing the amount of time spent outdoors, aiming for at least one to two hours daily, has been consistently linked to a lower risk of developing and progressing myopia, likely due to the exposure to bright natural light. Additionally, managing close work and screen time by following the “20-20-20 rule”—taking a 20-second break to look 20 feet away every 20 minutes—helps reduce eye strain.