Nearsightedness is now a real public health emergency, with prevalence rates steadily increasing worldwide and with marked differences between one continent and another, between one country and another, and between different socio-economic and cultural contexts.
Growth trends
The countries with the highest number of myopes are China, Japan, Singapore, Taiwan and all the Southeast Asian countrieswhere in urban areas there are 90% of children and adolescents with myopia by the end of high school, with 10% having high myopia.
Worldwide, the growth in myopia prevalence rates accelerated in the period of the COVID-19 pandemicwhen children and adolescents were forced to make massive use of digital devices and to live predominantly indoors, with very limited time outdoors.
The most recent estimates project the number of myopes in the 2050 over 740 million, considering only children and adolescents.
The causes
Nearsightedness arises in early childhood due to excessive elongation of the eyeball, tends to worsen as individuals progress from childhood to adolescence, and in some cases progresses into adulthood and can become pathological myopia.
Myopia is, by far, the most common refractive defect in the world. It is a condition with multifactorial aetiologybiological differences related to sex, gender, ethnicity and socio-economic background.
Its onset and progression are actually the result of a mix of genetic, epigenetic, environmental and hormonal factors. I school-age children are generally more susceptible and vulnerable to environmental factors than adults and this condition is particularly significant in the pre-school childrenwhich are still in a critical period of development of the visual apparatus, characterised by high plasticity.
Long-term risks
Preventing and controlling myopia in paediatric age means first of all ensuring a improved quality of vision for all future life and, moreover, constitutes a form of prevention against other eye diseases to which the myopic eye is more exposed than the emmetropic eye, such as glaucoma, myopic maculopathy and retinal detachment.
These pathologies occur more frequently in adulthood and old age, especially in individuals with high myopia, i.e. myopia reaching or exceeding 6 dioptres.
Contact Lenses and Bulb Length
Can something be done to counteract the progression of myopia? The answer is yes, and one possibility is to slow down the elongation of the eyeballespecially in the early years of onset of refractive defect, which means significantly reducing the risk of progression to high myopia and, consequently, preventing some very disabling eye diseases.
About 20 years ago, studies in orthokeratology, the ophthalmological technique aimed at correcting visual defects without resorting to surgery, ascertained that ocular elongation could be slowed down, and about 15 years ago, clinical research showed that the contact lensesparticularly soft multifocal LACs.
What is the mechanism of action that is exploited? In fact, profiles are created that differ in magnitude (power of peripheral addition), shape, and distribution. The most commonly used power profiles today are those of the centre distance multifocal lenses normally used for the correction of presbyopia, particularly if the addition is 2.50D or higher.
Alternatively, you can use the EDOF lenses to achieve an extension of the depth of focus (EDOF) by manipulating aberrations.
Further options are the dual focus lenseswith one or more concentric rings and, in addition, the frequently changed lenses can be custom-made, adapting the diameter of the myopic ring and their power to the refractive and myopic development characteristics of small patients. With this approach, good results could also be achieved in cases that, with standardised disposable lenses, are classified as unresponsive to treatment or with very rapid bulb growth.
Quality of vision
All these types of LACs necessarily induce, in addition to peripheral myopic defocus, a blurring on the central retina. Such blurring can adversely affect vision.
According to various scientific research data, peripheral myopic defocus lenses are on the whole well tolerated by the children up to the age of 12, while adolescents between the ages of 13 and 17 were more critical of the visual quality associated with these LACs.
Given all this, the two BLINK cohort studies (Bifocal Lenses in Nearsighted Kids) in which the effect in terms of myopia control of delayed eyeball length growth induced by wearing soft multifocal contact lenses was specifically evaluated and the hypothesis that the benefits in terms of reduced myopia progression persist when treatment is discontinued was tested.
The BLINK2 study included 235 young myopia patients, aged 11-17 years, 146 female (59%) and 102 male (41%), who completed the BLINK1 study, in which they were randomly assigned to wear multifocal or monofocal contact lenses for 3 years. In BLINK2, all subjects wore high-grade multifocal lenses (+2.50 diopters) and switched to monofocal lenses in the third year to check for a rebound effect. A slight myopia progression of 0.17D per year was observed regardless of treatment group in BLINK 1, but on average the axial length increased in line with the physiological growth rate, without loss of acquired benefit.
In Italy, paediatric ophthalmologists generally have a favourable attitude towards the use of LACs in myopic children, which are, however, only used to a very limited extent to date.
It is, therefore, to be hoped that paediatric ophthalmologists in particular will become increasingly familiar with these treatment options and the relevant clinical trials, since it is precisely thepaediatric ophthalmologist the interlocutor most trusted by parents in assessing the best treatment for their child's eye health.
In the field of paediatric ophthalmology see also
- The 'digital health' of children and young people - Oculista Italiano
- WHO guidelines: to reduce children's exposure to digital screens
- Eye pain in children: a symptom not to be underestimated
- Berntsen DA, Ticak A, Orr DJ, et al; Bifocal Lenses in Nearsighted Kids (BLINK) Study Group. Axial Growth and Myopia Progression After Discontinuing Soft Multifocal Contact Lens Wear. JAMA Ophthalmol. 2025 Feb 1;143(2):155-162. doi: 10.1001/jamaophthalmol.2024.5885
- Kido A, Miyake M, Watanabe N. Interventions to increase time spent outdoors for preventing incidence and progression of myopia in children. Cochrane Database Syst Rev. 2024 Jun 12;6(6):CD013549. doi: 10.1002/14651858.CD013549
- Liang J, Pu Y, Chen J, Liu M, et al. Global prevalence, trend and projection of myopia in children and adolescents from 1990 to 2050: a comprehensive systematic review and meta-analysis. Br J Ophthalmol. 2025 Feb 24;109(3):362-371. doi: 10.1136/bjo-2024-325427.
- Nixon A, Xu J, Brennan NA, et al. Subjective vision differences with soft contact lenses for myopia control in children and teenagers. Invest. Ophthalmol. Vis. Sci. 2023;64(8):4936.