How do myopia control contact lenses work?

They create peripheral myopic defocus by adding plus power in the peripheral zones of the lens while maintaining clear central distance vision. This peripheral optical signal is believed to slow axial elongation of the eye, reducing myopia progression. Standard single-vision correction creates peripheral hyperopic defocus that may stimulate eye growth.

What is MiSight and how effective is it?

MiSight 1 day (CooperVision) is the first FDA-approved daily disposable contact lens for myopia control in children ages 8-12. Clinical trials demonstrated approximately 59% reduction in myopia progression and 52% reduction in axial elongation over 3 years. It uses a dual-focus design with treatment rings that create peripheral myopic defocus.

At what age should myopia control be started?

Myopia control is typically most effective when started between ages 6-14, during the period of most rapid myopia progression. Children showing -0.50 D or more progression per year are good candidates. Earlier intervention generally provides more cumulative benefit over the growing years.

Myopia Control Contact Lenses: Peripheral Defocus Theory, MiSight, and Treatment Approaches

The Myopia Epidemic

Myopia (nearsightedness) is increasing worldwide at an alarming rate, with projections suggesting nearly half of the global population will be myopic by 2050. Beyond requiring optical correction, higher levels of myopia increase the risk of sight-threatening conditions including retinal detachment, myopic macular degeneration, glaucoma, and cataracts. Myopia control aims to slow the progression of myopia during childhood and adolescence when the eye is actively growing.

The Peripheral Defocus Theory

The scientific basis for myopia control contact lenses rests on the peripheral defocus theory:

Standard single-vision glasses and contact lenses correct central vision but create peripheral hyperopic defocus (light from the periphery focuses behind the retina)
This peripheral hyperopic defocus is believed to act as a growth signal, stimulating the eye to elongate axially to bring the peripheral image onto the retina
Myopia control lenses create peripheral myopic defocus (light from the periphery focuses in front of the retina) while maintaining clear central vision
Peripheral myopic defocus is thought to signal the eye to slow or stop elongation

Myopia control lenses work by changing how light focuses in the peripheral retina, not the central retina. Central vision remains clear for daily activities, while the peripheral optical signal is modified to reduce the stimulus for eye growth.

Multifocal Soft Contact Lenses

MiSight (CooperVision)

MiSight 1 day was the first FDA-approved contact lens specifically indicated for myopia control in children ages 8-12:

Daily disposable soft lens with a dual-focus design
Central zone corrects distance myopia for clear vision
Concentric treatment rings with added plus power create peripheral myopic defocus
Clinical trials demonstrated approximately 59% reduction in myopia progression over 3 years
Also showed approximately 52% reduction in axial elongation

Center-Distance Multifocal Lenses

Standard center-distance multifocal soft lenses (originally designed for presbyopia) have also shown myopia control effects:

The peripheral plus power zones create the same peripheral myopic defocus
Studies show varying efficacy depending on the add power and lens design
Higher add powers (+2.00 to +2.50 D) generally show greater myopia control effect

Orthokeratology for Myopia Control

Ortho-K provides myopia control through its corneal reshaping effect:

Central corneal flattening corrects myopia for clear daytime vision
Mid-peripheral corneal steepening creates a natural peripheral myopic defocus
Studies show approximately 40-60% slowing of axial elongation
Worn overnight, providing lens-free daytime vision that appeals to active children

Patient Selection

Myopia control is most effective when started early in the progression curve:

Age: Typically initiated between ages 6-14, when myopia progresses most rapidly
Progression rate: Most beneficial for children showing -0.50 D or more progression per year
Motivation: Both the child and parents must be committed to consistent lens wear
Maturity: The child must be capable of lens handling and hygiene with parental supervision
Parental myopia: Children with two myopic parents are at highest risk and may benefit most from early intervention

Monitoring and Follow-Up

Axial length measurement: The most objective measure of myopia progression. Optical biometry provides precise axial length that can be tracked over time
Cycloplegic refraction: Periodic cycloplegic refraction eliminates accommodation to measure true refractive error
Typical review schedule: Every 6 months during active treatment
Treatment duration: Often continued through the teenage years until myopia stabilizes naturally

Discontinuing myopia control treatment too early. Myopia often continues to progress through the teenage years. Stopping treatment at age 12 or 13 may allow rapid progression during the remaining growth years. Treatment decisions should be guided by axial length measurements and progression trends.

When discussing myopia control with parents, frame it as "slowing progression" rather than "stopping myopia." Setting realistic expectations helps maintain long-term compliance. Explain that even reducing progression by 50% significantly lowers the lifetime risk of myopia-related eye disease.

Key Takeaways

Myopia control lenses create peripheral myopic defocus to slow axial elongation
MiSight is the first FDA-approved myopia control contact lens, showing approximately 59% reduction in progression
Ortho-K provides 40-60% slowing of progression through corneal reshaping
Treatment is most effective when started early (ages 6-14) during rapid progression
Axial length measurement is the most objective way to monitor treatment effectiveness
Treatment should continue until myopia stabilizes, typically through the teenage years