# Can Special Lenses and Spectacles Slow Down Nearsightedness in Children? What Every Parent Should Know Myopia (nearsightedness) is a growing global health problem, and by 2050, half of the world's population may be affected. This CADTH Rapid Review examined four types of specialized lenses and spectacles—MiSight soft contact lenses, DIMS spectacle lenses, orthokeratology (OK) lenses, and multifocal contact lenses—to determine whether they can slow the worsening of myopia in children compared with standard single-vision lenses. Based on 5 systematic reviews and 7 randomized controlled trials (RCTs), the review found that all four interventions reduced both myopia progression and abnormal elongation of the eye's axial length, with some results statistically significant. However, the evidence has limitations, including small numbers of studies, limited safety data, and no long-term or cost-effectiveness data, meaning parents and clinicians should weigh the potential benefits carefully. # Can Special Lenses and Spectacles Slow Down Nearsightedness in Children? What Every Parent Should Know ## Table of Contents - Key Points - Understanding Myopia: The Basics - What This Report Set Out to Answer - How the Research Was Conducted - Key Findings: What the Evidence Shows - MiSight Soft Contact Lenses - DIMS Spectacle Lenses (MiyoSmart) - Orthokeratology (OK) Contact Lenses - Multifocal Contact Lenses - Frequently Asked Questions ## Key Points - Four specialty lens types slowed myopia progression and axial length in children compared to standard single-vision lenses. - DIMS spectacle lenses showed statistically significant benefit in one trial, but the result needs replication. - Orthokeratology had the largest evidence base, but overlapping systematic reviews mean findings are not fully independent. - No cost-effectiveness or long-term safety data were found for any of the four lens types. - Specialty lenses slow myopia but do not cure it; the goal is a lower final prescription and lower disease risk. - Clinical Implications: What This Means for Patients and Families - Study Limitations: What the Research Couldn't Prove - Recommendations for Parents and Caregivers - Source Information ## Understanding Myopia: The Basics Myopia—commonly called nearsightedness or short-sightedness—occurs when light rays entering the eye from distant objects focus *in front of* the retina instead of directly *on* its surface, making faraway objects look blurry. This happens because the cornea and/or lens is too curved, the eyeball is too long, or a combination of both factors. Eye doctors measure myopia using a unit called the spherical equivalent, expressed in dioptres (D). The technical definitions matter for understanding severity: - **Myopia:** a spherical equivalent of less than 0 dioptres - **Clinically significant myopia:** −1 D or less - **Moderate or high myopia:** less than −3 D Some children also have **anisomyopia**, a difference of more than 1 D in refractive status between the two eyes, or **anisometropia**, where the eyes have different refractive powers. These conditions can complicate treatment decisions. Nearsightedness becomes more common as children grow. In the United States, estimates show that myopia affects 1% to 5% of preschool children, roughly 9% of school-aged children, and about 30% of adolescents. If left untreated, myopia can progress to high myopia, and high levels of myopia are linked to serious eye diseases later in life—including glaucoma, macular degeneration, cataracts, and retinal detachment—which can lead to significant visual impairment and even blindness. The global picture is alarming. Myopia prevalence has risen worldwide and is now considered a global public health problem. Experts estimate that by 2050, half of the world's population will be nearsighted. That's why controlling myopia progression in childhood isn't just about clearer vision—it's about preventing future eye disease. Treatment options fall into two broad categories: optical interventions (various lens designs) and pharmaceutical interventions (such as atropine and timolol eye drops). For children, standard spectacles are typically the first step because they provide clear vision with few side effects. Contact lenses can be used, but they require greater dexterity and responsibility. Several specialized lens designs have been developed specifically to slow myopia progression, but there has been a lack of consensus about which ones actually work. This CADTH report focuses on four specific optical interventions: - **MiSight contact lenses (omafilcon A):** soft contact lenses with a large central correction area surrounded by concentric zones of alternating distance and near power - **DIMS spectacle lenses (MiyoSmart):** defocus incorporated multiple segments—glasses with a hexagonal central zone for distance correction, surrounded by an annular defocus zone containing dense microlens segments that add 3.5 D of defocus - **Orthokeratology (OK) lenses:** specially designed contact lenses, usually worn overnight, that temporarily reshape the cornea (the front surface of the eye) to improve vision during the day - **Multifocal contact lenses:** lenses with multiple focusing powers designed to reduce myopia progression ## What This Report Set Out to Answer The review asked eight specific research questions—four about clinical effectiveness and four about cost-effectiveness: 1. What is the clinical effectiveness of soft contact lenses (MiSight) for preventing myopia worsening in children? 1. What is the clinical effectiveness of DIMS spectacle lenses for preventing myopia worsening in children? 1. What is the clinical effectiveness of orthokeratology for preventing myopia worsening in children? 1. What is the clinical effectiveness of multifocal contact lenses for preventing myopia worsening in children? 1. What is the cost-effectiveness of MiSight lenses (questions 5–8 followed the same format for DIMS lenses, OK, and multifocal contact lenses)? For all four interventions, the review considered use alone or in combination with atropine eye drops, compared against standard single-vision lenses or spectacles. The outcomes of interest included myopia progression (measured by changes in spherical equivalent and axial length—the physical length of the eyeball), quality of life, medication side effects, infection risks, and medication adherence. For the cost-effectiveness questions, the review looked for data on quality-adjusted life-years and incremental cost-effectiveness ratios. ## How the Research Was Conducted CADTH (the Canadian Agency for Drugs and Technologies in Health) conducted this Rapid Review using a structured, transparent process. An information specialist carried out a limited literature search across major medical databases, including MEDLINE, the Cochrane Database of Systematic Reviews, the international HTA database, and websites of Canadian and international health technology agencies, plus a focused internet search. The search strategy combined controlled vocabulary (like the National Library of Medicine's MeSH terms) and keywords, focusing on pediatrics, myopia, and the specific lens types. The search was limited to human studies published in English between **January 1, 2016, and February 2, 2021**. One reviewer screened all citations and selected studies in two stages. First, titles and abstracts were reviewed. Then, potentially relevant articles were retrieved and assessed in full. Studies were excluded if they didn't meet the selection criteria, were duplicate publications, were published before 2016, or if their data was already captured in more comprehensive or more recent systematic reviews. For research question 2, primary studies that didn't specifically report the intervention as a DIMS spectacle lens were excluded, and for question 4, studies that didn't specifically report multifocal or bifocal contact lenses were excluded. The included publications were critically appraised using standard validated tools: AMSTAR 2 for systematic reviews, the ISPOR questionnaire for network meta-analyses, and the Downs and Black checklist for randomized controlled trials. Rather than calculating summary scores, the reviewer described the strengths and limitations of each study narratively. From 316 citations identified, 275 were excluded after title and abstract screening, leaving 41 potentially relevant reports for full-text review. Of those, 25 were excluded, and **16 publications met the inclusion criteria**. This final set comprised 1 overview of systematic reviews, 4 systematic reviews, and 7 randomized controlled trials—with one RCT reported across 4 publications and another across 2 publications. Notably, **no relevant economic evaluations were identified**, so the cost-effectiveness questions could not be answered. ## Key Findings: What the Evidence Shows The report found consistent—though not universal—evidence that all four specialized lens types slow myopia progression and reduce axial length elongation compared to standard single-vision lenses. Here's what the evidence showed for each intervention. ### MiSight Soft Contact Lenses (Omafilcon A) One randomized controlled trial evaluated MiSight contact lenses compared with single-vision lenses. The results showed that both myopia progression (worsening of the prescription) and axial length elongation (physical stretching of the eyeball, which is the structural driver of myopia) were **less with the MiSight lenses**. However, the RCT did not report whether the between-group difference was statistically significant—meaning we can't be certain the difference wasn't due to chance. More high-quality trials are needed before firm conclusions can be drawn. ### DIMS Spectacle Lenses (MiyoSmart) A single randomized controlled trial compared DIMS spectacle lenses—glasses with tiny lenslets built into the periphery—with standard single-vision spectacle lenses. The evidence showed that both myopia progression and axial length elongation were **less with the DIMS lenses**, and this time the between-group difference **was statistically significant**. This is an important finding because specialty spectacles are a non-invasive option that may be easier for younger children to manage than contact lenses. However, because the evidence comes from just one trial, the results still need replication. ### Orthokeratology (OK) Contact Lenses Orthokeratology—often called Ortho-K or corneal reshaping—had the largest evidence base in this review. Compared with single-vision contact lenses or single-vision lenses, the findings showed: - **Myopia progression was less with OK lenses** (reported in 2 systematic reviews and 2 RCTs; the between-group difference was statistically significant in some studies, while other studies did not report statistical significance) - **Axial length elongation was less with OK lenses** (reported in 5 systematic reviews and 2 RCTs; again, differences were statistically significant in some cases, while significance wasn't reported in others) The fact that five systematic reviews reached similar conclusions adds confidence to these findings. Still, the overlap between the primary studies included in those reviews means the evidence is not completely independent—the same underlying trials are being counted multiple times. ### Multifocal Contact Lenses Multifocal contact lenses also showed promising results. Compared with single-vision contact lenses, multifocal lenses reduced both myopia progression and axial length elongation (*1 systematic review and 2 RCTs; between-group difference was statistically significant*). This evidence base is smaller than for OK lenses, but the statistically significant results across multiple studies are encouraging. ## Clinical Implications: What This Means for Patients and Families For parents, the takeaway is that specialized lens designs offer real potential to slow the worsening of childhood myopia—and doing so matters far beyond the convenience of not needing stronger glasses. The connection between childhood myopia and adult eye disease is well established. High myopia significantly increases the lifetime risk of glaucoma, macular degeneration, cataracts, and retinal detachment. Slowing myopia progression in childhood—even by a modest amount—can reduce the final level of myopia a child takes into adulthood, potentially lowering the risk of these sight-threatening complications. Axial length is a particularly important measure: it reflects the actual physical change in the eye, and it's the metric most closely linked to future disease risk. Each lens type has practical trade-offs that families should discuss with their eye care provider: - **DIMS spectacles** are non-invasive and require no special handling, making them ideal for younger children. They showed statistically significant benefit, but real-world effectiveness outside of a research trial needs more study. - **OK lenses** offer the advantage of day-time freedom from glasses or contact lenses, since they're worn overnight to reshape the cornea. However, they require strict hygiene practices to prevent infection, and lens handling can be challenging for younger children. - **MiSight lenses** are daily soft contact lenses—a familiar format—but the evidence is currently limited to one trial that didn't report statistical significance. More research is needed. - **Multifocal contact lenses** showed statistically significant benefit but share the same hygiene and handling considerations as all contact lenses in children. **Important:** This report found **no economic evaluations** on the cost-effectiveness of any of these four interventions. That means we don't yet know whether the higher cost of specialty lenses (compared with standard spectacles) represents good value for health systems or for families paying out of pocket. ## Study Limitations: What the Research Couldn't Prove The CADTH authors were careful to point out the limitations of the evidence base. These are critical for families to understand when making treatment decisions: - **Limited quantity of evidence for some interventions.** MiSight and DIMS lenses were each evaluated in just one RCT, and multifocal lenses in only one systematic review and two RCTs. Orthokeratology had a larger evidence base, but— - **The studies overlapped significantly.** The five systematic reviews included many of the same primary studies, meaning the findings are not fully independent. This can create an illusion of more evidence than actually exists. - **Limited quality of primary studies.** Only 2 of the 7 RCTs masked both investigators and patients. In 4 RCTs, it was unclear whether masking occurred at all, which introduces potential bias. - **Sparse information on adverse events and safety.** The report notes limited information on side effects, risks of infection, and quality of life. This is especially relevant for contact lens interventions, where infection risk is a real concern. - **No long-term data.** The studies evaluated effects over relatively short periods. We don't yet know whether the benefits persist once the lenses are discontinued, or the long-term safety in children. - **No cost-effectiveness data.** None of the studies evaluated the economic value of these interventions, an important gap for decision-makers and families alike. - **Population limitations.** Most primary studies included Asian children, and the report noted the majority of studies were conducted in China, Spain, and the US. The applicability of findings to all ethnic and geographic populations may vary. ## Recommendations for Parents and Caregivers Based on this review, the following practical guidance can help families navigate the options: 1. **Talk to a pediatric eye care specialist.** Not all children are candidates for all lens types. Age, maturity, dexterity, hygiene habits, and the severity of myopia all matter. A comprehensive eye exam can help determine whether specialty lenses are appropriate. 1. **Consider starting with the least invasive effective option.** For many families, DIMS spectacle lenses may be a reasonable first step because they're non-invasive, show statistically significant benefit, and avoid the infection risks associated with contact lenses—but personalized advice is essential. 1. **Be realistic about the evidence for each lens type.** Orthokeratology has the most supporting evidence, but it carries the highest hygiene demands. MiSight lenses are a newer option with limited—but promising—data. Ask your eye care provider about the latest evidence for each specific brand and design. 1. **Don't skip safety precautions with contact lenses.** For OK, MiSight, and multifocal contact lenses, strict attention to lens cleaning, handling, and wear schedules is critical to minimize the risk of serious eye infections. Any pain, redness, or blurry vision while wearing contacts deserves immediate medical attention. 1. **Understand that not all cases of myopia need specialty lenses.** For children with mild myopia that is progressing slowly, standard spectacles may be perfectly adequate. The decision to use specialty lenses should weigh the added cost and potential risks against the expected benefit. 1. **Ask about combination treatment.** Some of the inclusion criteria in this review allowed for lenses combined with atropine eye drops. Low-dose atropine has its own evidence base for slowing myopia, and your provider may discuss combining approaches. Ask specifically about what the evidence supports. 1. **Keep reasonable expectations.** These lenses slow down progression; they don't cure myopia. Most children will still need some kind of vision correction, but ideally they will end up with a lower final prescription and a reduced lifetime risk of serious eye disease. 1. **Watch for future research updates.** The field is moving quickly. New RCTs, longer-term follow-up, and economic evaluations are needed to fill the gaps identified in this review. Your eye care provider may be able to tell you about emerging options. ## Frequently Asked Questions ### What is myopia and why does it matter? Myopia, or nearsightedness, makes distant objects blurry because light focuses in front of the retina. It often starts in childhood. If untreated, it can reach high levels, raising lifetime risks of glaucoma, macular degeneration, cataracts, and retinal detachment. Experts estimate that by 2050, half the world may be nearsighted. ### Can special lenses or spectacles really slow down myopia in children? This review found that all four specialized lens types—MiSight, DIMS spectacles, orthokeratology, and multifocal contacts—reduced myopia progression and eyeball elongation compared with standard single-vision lenses. However, the evidence has limitations, including few studies, limited safety data, and no long-term results, so benefits should be weighed carefully. ### How well does the DIMS spectacle lens (MiyoSmart) work? In one randomized trial, DIMS spectacle lenses significantly reduced both myopia progression and axial length elongation compared with standard spectacles. This is promising because they are non-invasive and easy for young children. However, only one trial exists, so results have not yet been replicated in independent studies. ### Are MiSight contact lenses effective for slowing myopia? One randomized trial tested MiSight contact lenses against single-vision lenses. Both myopia progression and axial length elongation were less with MiSight, but the trial did not report whether this difference was statistically significant. This means the benefit could be due to chance, and more high-quality trials are needed before firm conclusions. ### Do we know if these lenses are cost-effective? No. The review identified no economic evaluations for any of the four lens types. This means we do not yet know whether the higher cost of specialty lenses, compared with standard spectacles, offers good value for health systems or for families paying out of pocket. Families should discuss costs with their provider. ### When should parents consider a second opinion about using specialized lenses or spectacles to slow their child's nearsightedness? Parents may seek a second opinion when choosing among MiSight contacts, DIMS spectacles, orthokeratology, or multifocal contacts, because each has different evidence strength, safety demands, and costs. All four slowed myopia progression and axial elongation compared with single-vision lenses, but only DIMS and multifocal contacts showed statistically significant differences in some studies; MiSight evidence came from one trial without reported significance. No long-term or cost-effectiveness data exist. A second opinion can help weigh these trade-offs. Diagnostic Detectives Network provides independent expert second opinions. ## Source Information This patient-friendly article is based on the following peer-reviewed research: - **Original title:** Lenses and Spectacles to Prevent Myopia Worsening in Children - **Authors:** Srabani Banerjee, Jennifer Horton - **Publication:** CADTH Health Technology Review, Rapid Review, April 2021, Volume 1, Issue 4. ISSN: 2563-6596 - **Publisher:** Canadian Agency for Drugs and Technologies in Health (CADTH), an independent, not-for-profit organization that provides Canada's health care decision-makers with objective evidence about drugs, medical devices, diagnostics, and procedures. *This patient-friendly article is based on peer-reviewed research and is intended for informational purposes only. It is not a substitute for professional medical advice. Always consult a qualified eye care professional about diagnosis and treatment for your child. The original CADTH report noted that the views expressed do not necessarily represent the views of Canada's federal, provincial, or territorial governments.* --- Publisher: Diagnostic Detectives Network (https://diagnosticdetectives.com) — independent multi-expert medical second opinions, worldwide, private-pay. Author byline: Anton Titov, MD, PhD. 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