Biswas et al.
Journal of Physiological Anthropology(2024) 43:7
https://doi.org/10.1186/s40101-024-00354-7

Journal of
Physiological Anthropology

Open Access

REVIEW

The influence of the environment
and lifestyle on myopia
Sayantan Biswas1†, Antonio El Kareh2†, Mariyem Qureshi1, Deborah Mei Xuan Lee3, Chen‑Hsin Sun4,
Janice S.H. Lam4, Seang‑Mei Saw5,6,7 and Raymond P. Najjar4,5,6,8*   

Abstract
Background Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost
one in three individuals across the world. The increasing prevalence of myopia during early childhood has heightened
the risk of developing high myopia and related sight-threatening eye conditions in adulthood. This surge in myopia
rates, occurring within a relatively stable genetic framework, underscores the profound influence of environmental
and lifestyle factors on this condition. In this comprehensive narrative review, we shed light on both establishedand potential environmental and lifestyle contributors that affect the development and progression of myopia.
Main body Epidemiological and interventional research has consistently revealed a compelling connection
between increased outdoor time and a decreased risk of myopia in children. This protective effect may primarily
be attributed to exposure to the characteristics of natural light (i.e., sunlight) and the release of retinal dopamine.
Conversely, irrespective of outdoor time, excessive engagement in near work can further worsen the onset of myopia.
While the exact mechanisms behind this exacerbation are not fully comprehended, it appears to involve shifts in rela‑tive peripheral refraction, the overstimulation of accommodation, or a complex interplay of these factors, leading
to issues like retinal image defocus, blur, and chromatic aberration. Other potential factors like the spatial frequencyof the visual environment, circadian rhythm, sleep, nutrition, smoking, socio-economic status, and education havedebatable independent influences on myopia development.
Conclusion The environment exerts a significant influence on the development and progression of myopia.
Improving the modifiable key environmental predictors like time spent outdoors and engagement in near work can
prevent or slow the progression of myopia. The intricate connections between lifestyle and environmental factors
often obscure research findings, making it challenging to disentangle their individual effects. This complexity under‑scores the necessity for prospective studies that employ objective assessments, such as quantifying light exposureand near work, among others. These studies are crucial for gaining a more comprehensive understanding of how vari‑
ous environmental factors can be modified to prevent or slow the progression of myopia.
Keywords Myopia, Epidemiology, Emmetropization, Genetics, Environment, Light, Outdoor time, Etiology, Risk
factors, Progression†

Sayantan Biswas and Antonio El Kareh contributed equally to this work.

*Correspondence:
Raymond P. Najjar
rpnajjar@nus.edu.sg
Full list of author information is available at the end of the article© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which
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Biswas et al. Journal of Physiological Anthropology(2024) 43:7

What is myopia?
Myopia or near-sightedness is a refractive error that is predominantly caused by a mismatch between the opticalpower of ocular components (i.e., the cornea and the crystalline lens) and the axial length (AL) of the eye whereby
light entering the eye is focused anterior to (in front of) the
retina, leading to the blurred vision of distant images [1,2]. In axial myopia, an excessive antero-posterior elongation of the eyeball occurs with thinning of the retina, choroid, and sclera [1] (Fig. 1). This excessive axial elongation ishypothesized to trigger sub-foveal chorio-retinal stretching,increasing the risk of sight-threatening ocular diseases suchas posterior staphyloma, retinal degeneration, and glaucoma[3]. On the other hand, refractive myopia is predominantly
associated with steepening of the cornea and lens curvature
which increases the optical power of the eye [1].
Blurred distance vision due to myopia can be corrected using negative (concave) spectacles or contactlenses that refocus the image on the retina [4]. The
power of the corrective lens in diopters (D) reflects thedegree/severity of myopia [5]. For an eye to be considered myopic, the spherical equivalent refractive error(spherical refraction + 0.5 * cylindrical refraction) withocular accommodation relaxed must be ≤ −0.50 D. In
high myopia, the spherical equivalent refractive error
when ocular accommodation is relaxed is ≤ −5.00 D [6].
Myopia is a public health concern
The prevalence of myopia is not homogeneous acrossthe globe. In school children (6–19 years old), thehighest myopia prevalence was reported in Asia (60%;Page 2 of 22

including East Asia (73%)), followed by North America (42%), Europe (40%), South America (~10%), andAfrica (3.4–4.0%) [7]. In young adults, the prevalence
is much higher in urban East Asian countries (81.6–
96.5%) than in the rest of the world (12.8–35.0%) [8].
In comparison, the prevalence of adult myopia was
19.4–41.8% among East Asians, 17.2–36.5% in therest of Asian countries, and 11.4–35.1% among nonAsians [8]. The worldwide prevalence of myopia ison the rise for reasons that are still not well understood [7, 9–11]. A systematic review and meta-analysis of 145 studies worldwide on myopia prevalence
predicted that by 2050, half of the world population(4,758 million people) will be myopic and ~10% of theworld population (938 million people) will have highmyopia. [12]. In Europe, however, findings are mixed,with both reports of an increase [13] and no change inmyopia prevalence [14].
In addition to being a public health concern, myopia is also a health economic burden. There are several estimates for the global financial burden related
to myopia (i.e., the health expenditure and loss of productivity), all of which are in the range of several hundred billion dollars per year [9]. High myopia increases
the risk for other sight-threatening ocular conditions
like retinal detachment, glaucoma, and cataract [15,16]. Also, both uncorrected myopia and pathologic
myopia (characterized by lesions in the fundus likestaphyloma, neuropathy, and maculopathy) are associated with reduced quality of life [9]. Hence, investigating the disease process, epidemiology, etiology, andFig. 1 Schematic of emmetropia and axial myopia. A In an emmetropic eye, parallel rays of a distant object are focused on the retina. B Whenan eye is tasked to focus on a near object, without accomodation, the image of the object is focused behind the retina. C Accommodation canbring forward the image to focus on the retina. D In axial myopia, the eye’s axial length has grown longer than the dioptric focus of the eye.
Light rays are therefore focused in front of the retina resulting in the blurred vision of a distant object. E Myopia can be optically corrected using
a concave lens (spectacles or contact lenses) which diverges the light rays and moves the image into focus on the retina

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

risk factors for myopia in addition to emerging therapeutic strategies for this condition is essential in halting the myopia epidemic.

Clinical features of myopia
Refractive error is typically measured by means ofobjective (i.e., autorefractor) or semi-objective (retinoscopy; objective from the patient’s perspective but
not the operator’s as it requires examiner skill) techniques as a starting point before subjective refraction.
Accommodation induced by the eye’s ciliary muscles
can influence refractive error, inflating the prevalenceand degree of myopia by 0.63 to 0.89 D in children
with active accommodation [17]. The gold standard for
accurate subjective refraction is cycloplegic refraction,
which involves using pharmacologic agents that temporarily paralyze the ciliary muscles and accommodation. Alternatively, open-field autorefractors reduce
the effect of residual accommodation and instrument
myopia, are more repeatable and precise, and minimize investigator bias [17].
AL is measured as the axial distance between the anterior corneal surface to the retina (inner limiting membrane or retinal pigment epithelium depending on thetechnique used) along the line of sight. AL is highly correlated with the refractive error [18] with approximately
a 2.3 D increase in myopia associated with a 1-mmincrease in AL and vice versa [19]. AL can be measured
using ultrasound biometry, optical biometry, and opticalcoherence tomography (OCT) techniques [17].
An increase in the corneal steepness and power (i.e.,decrease in radius of curvature) increases myopic refraction and vice versa [20]. Corneal curvature and the corresponding power can be measured using keratometry anda wide range of corneal topography and anterior segment
imaging devices.
Choroidal (inner sclera to outer retinal pigment epithelium (RPE)), retinal (internal limiting membrane toBruch’s membrane), and sub-foveal scleral (chorio-scleralinterface to the outer scleral border) thinning are also
observed in myopic eyes. These structural assessments
can be measured using posterior segment OCT devices
with enhanced depth imaging (EDI) [21], wide field/highpenetration swept source OCTs [22, 23], and magnetic
resonance imaging [24].
Emmetropization and myopia development
Emmetropization is a visually guided phenomenon that
occurs from birth and regulates axial ocular growth tomatch the eye’s focal length with its focal power. Abnormal emmetropization, or its maintenance, is the fundamental problem in myopia development. This can be
induced experimentally in a variety of ways. Depriving

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the eye in animal models from spatial vision results inocular axial elongation and subsequent form deprivation
myopia (FDM). Form deprivation can be induced in animals by eyelid sutures [25–28], translucent diffusers, or
frosted goggles which reduce the sharpness and contrast
of retinal images [29]. Clinically, FDM is reported in ocular conditions such as congenital ptosis and cataracts,
which deprive the eye of visual stimulation [30–32].
Compensatory ocular growth towards emmetropization is also driven by hyperopic or myopic defocus at theretina. Several animal species, most commonly chicks
wearing positive or negative lenses were found to exhibit
a rapid change in eye growth to compensate for the
defocus and attain emmetropia [33]. Hyperopic defocus(image behind the retina) is generated by negative lenses
which stimulate axial elongation, while myopic defocus(image in front of the retina) generated by positive lenses
inhibits axial elongation [34–36]. The eye can decipher
between myopic and hyperopic blur/defocus and alter
its growth accordingly.
Emmetropization has two phases, a rapid infantile
phase, and a slower juvenile phase. The rapid infantile phase starts between 3 and 9 months of life, wherea myopic shift in refraction towards low hyperopia or
emmetropia occurs [37, 38]. During that phase, a fast
increase in AL (~5 mm) is accompanied by compensating changes in ocular structures resulting in corneal andlens power reduction [39]. Concomitantly, new-born(3 months old) have an average cycloplegic hyperopic
refraction of about +2 D, which rapidly reduces to +0.75
D by the time they reach 3.5 years of age [40]. The AL
increases from an average of 15 mm in new-born to 24
mm by early adulthood and is counteracted by an equaland opposite change in corneal and lens power [41]. The
slower juvenile emmetropization phase starts at 3 years
and continues till adolescence [42]. Similarly, during thisphase, AL grows along with changes in the cornea andlens, albeit at a much slower rate [42]. The majority ofmyopia onset occurs during this phase, often between
ages 6 and 9 years [43, 44], followed by a rapid phase of
myopic shift in refractive error, which plateaus by early
adulthood [40]. Myopia onset, after the primary emmetropization period, can result from the failure to maintainan emmetropic state and not a failure of the emmetropization process [40]. The earlier the age of myopia onset,
the higher the risk for high myopia and associated sightthreatening conditions. Hence, delaying the onset of
myopia may delay or prevent pathological myopia [45].

Genetic factors influencing myopia
Parental myopia significantly influences a child’s likelihood of developing myopia. For instance, the proportionof children developing myopia is 32.9%, 18.2%, and 6.3%

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

with two, one, and no myopic parents, respectively [46].
Among a predominantly white population (89.1%), theodds of being a myope also increase from one (odds ratio(OR), 3.32) to two parents (OR, 6.40) with myopia [46].
Whereas in a mixed population, the ORs were 1.42 for
one parent, 2.70 for two parents, and 3.39 for two parents
with early onset myopia, respectively [47]. These findings
are corroborated by longitudinal cohort studies with follow-ups of 7 and 22 years [48, 49]. In addition, genomewide association studies (GWAS) and their meta-analyses
have helped identify several single nucleotide polymorphisms (SNPs) associated with myopia [50–53]. Nonetheless, common SNPs identified through GWAS thus
far can only explain 18.4% of spherical equivalent heritability [51]. The effect sizes of SNPs associated with myopia are small, in the order of ±0.1 D [54]. Thus, association
with parental myopia (i.e., inheritance or heritability) does
not necessarily mean genetics are causative of myopia.
The surge in myopia prevalence worldwide, occurring
without significant genetic changes between generations,suggests a considerable role of behavior-influenced environmental and lifestyle factors in myopia development[55, 56]. In the following paragraphs, we highlight some of
the most prominent environmental and behavioral factorsthat have emerged as significant contributors to the onset
and progression of myopia in children.

Environmental factors influencing myopia
Time spent outdoors

Both cross-sectional and longitudinal studies havereported a significant association between increased
time spent outdoors and reduced myopia prevalence.
Numerous cross-sectional studies including the Sydney myopia study (SMS) (n=2367, 12 years old) [57], theSingapore Cohort of Risk factors for Myopia (SCORM)(n=1249, 11–20 years old) [58], the Beijing Myopia Progression Study (BMPS) (n=386, 6–17 years old) [59],among others, have independently reported a significant
association between increased time outdoors and lower
myopia rates and vice versa. Likewise, longitudinal studies including the Avon Longitudinal Study of Parents andChildren (ALSPAC) (n=4837–7737, 7–15 years old) [60],the Sydney Adolescent Vascular and Eye Study (SAVES)(n=2103, 6 and 12 years old) [61], the Collaborative Longitudinal Evaluation of Ethnicity and Race (CLEERE)(n=731, 6–14 years old) [62], and the Orinda Longitudinal Study of Myopia (OLSM) (n=514, 8–9 years old)[63], confirmed these associations between delayed myopia onset and increased time spent outdoors. Australian children spending more time on outdoor activities(13.75 vs 3.05 h/week) [64] and longer daily outdoor light
exposure (105 vs 61 min/day) [65] were found to have alower prevalence of myopia (3.3%) [64] than Singaporean

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children (29.1%). Interventional randomized controlled
trials (RCT), two in Chinese (n=6925, 6–9 years old,n=3051, 6–14 years old, and n=1903, 6–7 years old) [66,67] and two in Taiwanese (n=571, 7–11 years old and
n=693, 6–7 years old) [68, 69] school children demonstrated that incorporating 40 to 80 min of interrupted
recess time outdoors reduces myopia incidence. However, it should be noted that the reporting of light exposure using questionnaires in these studies may be more
prone to reporting bias compared to objective measures[70]. A recent RCT [71] evaluating the protective effectof 0, 40, and 80 min of additional time outdoors among
6–9 years old Chinese school children for over 2 years
observed a dose-response relationship between the outdoor exposure time and myopia onset and progression.
The protective effect was associated with the objective
measurement of both the duration of exposure and lightintensity. Likewise, recent systematic reviews and metaanalysis [72–76] along with their overviews [77, 78] reinforce the compelling protective impact of time spent
outdoors against myopia and highlight a 2–5% reduced
OR of prevalent myopia and 24–46% reduction in relative risk of incident myopia for every additional hour of
outdoor time per week.
While parents are being advised to promote outdoor
activity for their children, a systematic review of evidence
suggests increased time outdoors is effective in preventing the onset of myopia but is not effective in slowing the
progression in eyes that are already myopic [73]. However, interventional studies have demonstrated that myopia progression can indeed be mitigated by increasing thetime spent outdoors [66–69], and a recent meta-analysis
has reaffirmed this effect, revealing a pooled reduction
effect of 0.13 to 0.17 D in myopic refractive error per
year [78]. Conversely, the substantial uptick in indoor
time and a reduction in outdoor activities among schoolchildren during the COVID-19 pandemic-related homeconfinement was linked to a rise in both the incidenceof myopia and the rate at which it progressed [79, 80]. It
is worth mentioning that some studies like the CLEERE[81], Anyang Childhood Eye Study (ACES) [82], amongst
others [83–85], found no associations between the duration of time spent outdoors, the incidence of myopia,
and its progression. These disparities in findings may
stem from variations in cohort age, study duration, andresearch design, as well as differences in the criteria used
for classifying myopia.
The protective effect of time outdoors against myopia has primarily been attributed to the level and spectral compositions of daylight (i.e., high light levels, broad
spectral distribution) [29, 86, 87], the visual-spatial characteristics (i.e., high spatial frequency), and accommodative profiles (i.e., less variation and demand) [88, 89] ofBiswas et al. Journal of Physiological Anthropology(2024) 43:7

the environment outdoors, all lacking in most indoor
environments, especially in schools. In the sections
below, we discuss the “independent” effects of these environmental features on myopia.
Features of the lighting environment

Lighting characteristics such as intensity, spectral composition, duration, pattern, and timing can synergisticallyaffect ocular growth and development [29].
Light levels

Indoor illuminances generally range between 10 and1000 lux, whereas outdoor light levels on a cloudy day orunder shade can vary between 10,000 and 30,000 lux [86]and reach more than 100,000 lux [90, 91] on a sunny day.
Low daily light exposure measured using objective wristworn light sensors has been associated with greater axial
elongation and myopia [92]. Concurrently, exposure toboth long-term [93] and short-term (30–120 min) light[94, 95] of moderate levels of illumination (500–1000 lux)
induces a significant reduction in axial elongation andan increase in choroidal thickness (CT) in young adults.
Low illumination levels (359 vs 671 lux) in the nursery(4–5-year-old children) [96] and the lowest daylight factor in elementary (6–7-year-old children) [97] schoolclassrooms were suspected to be associated with myopia
and axial elongation. Similar results echoed in a 1-year
RCT (n=1713, 6–14-year-old children) with higher ambient light levels of 558 lux vs 98 lux at the desk and 440 lux
vs 76 lux at the blackboard being protective against theonset and progression of myopia and ocular axial elongation [98].
Animal studies further provide evidence supporting
the protective effect of high illuminance against myopia.
Chicks [36, 91, 99, 100], infant monkeys [101], and guinea
pigs [102] exposed to high-intensity light (≥10,000 lux)for 5–6 h/day showed reduced experimental myopia
development.
Spectral composition of light

In addition to light levels, the spectral composition oflight can affect emmetropization and myopia development. Compared to the most frequently used artificial light sources indoors (e.g., fluorescent, lightemitting diodes (correlated color remperature (CCT):
2000 K – 6500 K), halogen), the spectrum of sunlight is
dynamic across the day and has a fuller distribution of
wavelengths [87]. Natural sunlight contains ultra-violet(UV), near-infrared, and infrared (IR) wavelengths oflight (Fig. 2A–C, Fig. 3). The effect of different wavelengths of light on myopia development is still not wellunderstood, especially in humans. Torii et al. showedthat UVA light (360–400 nm), absent in commonly used

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indoor lights (Fig. 2E), could suppress myopia progression and reduce axial elongation in humans through theupregulation of the transcription factor early growth
response factor-1 (EGR-1), encoded by the EGR1 gene[103], and via neuropsin (OPN5) stimulation in mice[104]. In an RCT on 6–12-year-old Japanese children(2-year follow-up), violet light-transmitting glasses were
found to reduce axial elongation by 21.4% compared to
glasses that do not transmit violet light. However, theeffect was significant only in the sub-group of those performing <180 min of near work or first-time glass users[105]. A 6-month randomized pilot study on using violet
light-emitting glasses for 3h/day had a small but significant protective effect on AL elongation in 8–10-year-old
children. However, the sample size was only 10 and theeffect was not significant for younger (6–7 years) or older(11–12 years) children [106]. Further investigations are
warranted to assess both the efficacy and safety of UVA
light exposure for myopia control. Similarly, in a laboratory setting, exposure to short wavelength blue light(460 nm) for 1 h was found to reduce axial elongation
in young adults (20–32 years) compared to both green(521 nm) and red light (623 nm) [107]. Likewise, thestimulation of blind spots (optic nerve head) using flickering blue light (peak 450 nm) for 1 or 10 min increases
retinal activity (increases b wave amplitude of bipolarcells) [108]. This intervention was built around the factthat blue light would stimulate melanopsin present in
the axons of intrinsically photosensitive retinal ganglion
cells (ipRGCs) having synaptic connections with dopaminergic amacrine cells, thus modulating the releaseof the neurotransmitter dopamine (DA) [108]. With
DA regulating ocular growth (see the section “potential mechanisms for light-driven myopia prevention andcontrol” below), this effect may have an implication formyopia control. It is also possible that longitudinal chromatic aberration focusing various wavelengths of lightdifferently relative to the retina, alters the outdoor effecton myopia by providing a visual cue (directional) during
emmetropization [109]. A recent clinical study reported
that 2 h of non-objective outdoor sunlight exposure(average 6000–50,000 lux) promotes choroidal thinningand retinal thickening compared to indoors (350 lux) anddark (<0.1 lux) [110]. This contrast from previous findings of a transient increase in CT on the application oflight exposure (indoor LEDs) [94, 95] is probably becauseof the differences in experimental protocol and lack ofcontrol over the confounders such as the visuo-spatialenvironment [89], caffeine intake [111], smoking [112]preceding, and during the 2-h long unsupervised outdoor
activity. On the other end of the visible light spectrum,
several randomized clinical trials (6–24 months of follow-up) have shown great promise that repeated low red

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

Fig. 2 Spectral power distribution of light in different environments, both outdoors (O) and indoors (I)Page 6 of 22

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

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Fig. 3 A direct comparison of the levels and spectra of light measured indoors and outdoors. A Light levels outdoors are significantly higher
than light levels indoors. B The light spectrum outdoors remains fairly unaltered when measured in different locations. Conversely, light levels
outdoors can decrease by ~1 log unit between an open field and a denser building area or even indoors looking out from a window. Conversely,
light levels can drop by more than 10 log units in a room equipped with artificial lighting. C The spectral power distribution of the averagemeasurements outdoors (±SEM) compared to indoor scenarios. D, E, and F Normalized spectral power distribution of light outdoors comparedto light indoors. While the spectrum remains fairly similar between 400 and 650 nm, windows block a considerable amount of ultra-violet (<400nm) and near-infrared or infrared light (>650 nm) (D). Similar differences are observed between traditional indoor LED lighting (CCT: 4000 K)
in addition to reduced composition in wavelengths between 400–440 nm and 480–560 nm (E). Similar observations can be made when comparing
artificial lighting to sunlight seen through a window (F)light (RLRL) (640 nm) administered for 3 min twice a day
can slow myopia progression in children aged 7–15 years
old [113, 114]. The strength of evidence for RLRL was,however, low, with large rebound effects reported afterits discontinuation [115]. Furthermore, there have beensafety concerns associated with RLRL, including reportsof an isolated case of retinal damage that may potentiallybe linked to the procedure [116].
In addition to studies in humans, experimental studies in animal models have also shown that different
wavelengths of light have distinct effects on myopia

development. While shorter wavelengths of light (290–495 nm) [103, 104, 117–125] have been shown to be protective against experimental myopia in chicks, mice, andguinea pigs, longer wavelengths (570–636 nm) of light[126–131] were found to be protective in tree shrews
and some non-human primates. This variation in spectral response among different species may be attributed
to several factors, including differences in retinal photoreceptor structure, sensitivity, and variations in experimental protocols such as the duration of light exposure
and its intensity [29, 124]. In addition, recent studies

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

demonstrated that sun-like and blue-enriched light spectra, even at low-moderate illuminances (200–400 lux),
can slow the development and accelerate recovery from
FDM in chicks [132, 133].
A comparison of light levels and spectra between different
environments

As mentioned in the paragraphs above, light levels andspectra differ greatly between indoors and outdoors[29, 134]. To better highlight these differences, we performed the study below. The spectral power distributionof ambient light was measured at the eye level in different outdoor and indoor locations using a calibrated
spectroradiometer (ILT950, International Light Technologies, Peabody, MA, USA). In an open field, outdoor
light intensity is at its highest, with the sun serving as
the sole light source (Fig. 2A). As urbanization gradually
becomes evident, such as between buildings with open
tops (Fig. 2B), the spectral distribution remains similar
but with a diminished light intensity. Further urbanization, as seen when measuring light outdoors but under ashelter with a covered roof (Fig. 2C), results in reduced
ambient light intensity while preserving a similar spectral distribution. However, the introduction of modern
urbanized buildings, even with a window view, leads
to a drastic alteration in the indoor spectral distribution of available light, although light intensity remains
comparable (Fig. 2D). Subsequently, when we bring thefull extent of urbanization indoors in a setting devoidof windows and illuminated by LED light (Fig. 2E), we
observe a further modification characterized by bothdecreased intensity and a shift in the spectral distribution, now manifesting as two peaks at approximately 450
nm and 600 nm.
When performing a direct comparison of light levels and spectra measured both indoors and outdoors(Fig. 3), outdoor light levels are significantly higher thanthose encountered indoors (Fig. 3A). The outdoor light
spectrum remains relatively consistent across different outdoor locations, but light levels can decrease by atleast one log unit when transitioning from an open field
to a more densely built area or even when viewing fromindoors through a window (Fig. 3B). Conversely, indoor
light levels can drop by over 10 log units in spaces withartificial lighting (Fig. 3B, C). The natural light spectrum
outdoors and indoors (through a window) remains fairly
consistent between 400 and 650 nm, while windows
block a significant portion of ultraviolet light (<400 nm)
and near-infrared or infrared light (>650 nm) (Fig. 3D).
Similar differences are observed when comparing traditional indoor LED lighting (CCT: 4000 K), with reduced
composition in wavelengths between 400–440 nm and
480–560 nm (Fig. 3E). Comparable distinctions can be

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observed when contrasting artificial lighting with sunlight seen through a window (Fig. 3F).
Given the evident disparities between natural outdoor light and current indoor lighting, it has become
imperative to urgently curate and tailor indoor lighting
environments, whether artificial or natural, to promotehealthier ocular development in children [135]. This is
critical within educational settings, such as classrooms,
where children predominantly spend their daylight
hours.
Timing, duration, and pattern of light exposure

Experimental animal research findings suggest that thetiming, duration, and pattern of light exposure can influence myopia. For instance, moderate light during midday (2000 lux) is more effective at reducing myopia thanevening exposure in chickens [136]. Longer light exposures (2000 lux for 10 h) can be more effective than anequivalent dose of shorter, but brighter exposures (10,000
lux for 2 h), irrespective of the exposure time-of-day(morning, mid-day, or evening) [136], whereas intermittent exposure to high illuminances of light (15,000 lux)
may be more effective than continuous light of equal
duration and illuminance against FDM in chickens [137].
On the other hand, constant light (i.e., for 24 h) can disrupt the emmetropization process [138] and evening
exposure to light (700 lux) was reported to disrupt thecircadian rhythm of ocular growth [139, 140]. The frequency of a light flicker also modulates eye growth withlow frequency stimulating and high frequency reducing
eye growth [141]. It is worth mentioning that the distinctive effect of these light features has been understudied inhumans.
Potential mechanisms for light‑driven myopia prevention
and control

Modulations in ocular neurotransmitters and signaling
molecules: DA, a neuromodulator, is the most widely
studied neurotransmitter and is proposed to influenceeye growth and the emmetropization process [142]. DA
is released by the amacrine and/or inter-plexiform cellsof the retina [143, 144] and has a dose-response relationship with the intensity of light [145–147]. Even intermittent light exposure was found to be more effective thancontinuous light of equal duration possibly because of theactivation of retinal ON and OFF pathways by flickering
light, stimulating DA release [148]. Animal studies implicated DA activity to mainly mediate via the D2 receptor
pathway, although D1 and D4 (D2-like receptors) also
play some role in refractive development, which remains
controversial [149]. Even though DA levels get directly
influenced by the duration and intensity of light, DA isBiswas et al. Journal of Physiological Anthropology(2024) 43:7

also found to be released under dark conditions, following the circadian pattern of its release [150] and rod cell
activation [151]. Furthermore, DA agonists [152, 153] andantagonists [99] were also used to support the role of DA
in axial elongation. However, there are no clinical studies linking DA and myopia due to the obvious limitationof accessing human ocular tissue. DA is also known tomodulate CT and axial growth by triggering the releaseof other neurotransmitters, such as nitric oxide (NO)[142, 154, 155]. NO was found to be dependent on lightlevels and reduces FDM [156]. Other neurotransmittersand signaling molecules linked with light and myopia areatropine, 5-hydroxytryptamine (5-HT), EGR-1 (ZENK),
gamma-aminobutyric acid (GABA), retinoic acid (RA),melanopsin, and ipRGCs [29, 142, 155].
Blood flow DA enhances retinal perfusion and choroidal blood flow in humans [157]. Reduced ocular bloodflow can be implicated as a potential cause for choroidal
and retinal thinning and associated eyeball elongation in
myopia. To support this theory, lower ocular blood flow
has been frequently reported in myopic eyes [158]. However, it is unclear whether reduced blood flow is a primary change that causes secondary thinning of the choroid and retina or quite the opposite, i.e., the mechanicalstretching of the eye reduces its wall thickness and causes
a secondary lower demand for oxygen.
Vitamin D Vitamin D is available in small amounts
from food such as fish and eggs, but the majority is synthesized in the skin on exposure to sunlight (UVB). Several cross-sectional studies found lower levels of vitamin
D in myopes compared to non-myopes [159–163]; however, subsequent studies found no such evidence [164,165]. A review of time outdoors, vitamin D, and its association with myopia found an interrelation but without
any biological plausibility [166]. Moreover, myopia is nota characteristic feature associated with rickets (vitamin D
deficiency) which suggests vitamin D may indicate time
outdoor levels (UVB exposure) but not have any protective effect itself [167].
Spatial frequency and other environmental visual features

The spatial frequency of the visual environment strongly
differs between indoor and outdoor sceneries [88]. Urban
outdoor environments were found to lack greenery andhigh spatial frequency with defocused retinal images
which is similar to the image generated using diffusers
to induce FDM in animals [89]. On the contrary, imagesof greenery contain significantly higher spatial frequency
content [89]. The level of residential greenness in Spain
and China has been reported to reduce spectacle use
and the risk of myopia among preschool and school

Page 9 of 22

children [168–170]. While these benefits could potentially be attributed to a reduction in daily screen time[168], it is important to consider that changes in spatial
frequency and exposure to natural light may also be contributing factors. Animal studies found intermediate andmixed spatial frequencies to reduce FDM compared toboth high and low spatial frequencies in chickens [171,172]. Besides, accommodative micro-fluctuations werealso found to be dependent on the spatial frequency ofimages, with the lowest fluctuation at medium spatial
frequency [173, 174]. Further studies are required to elucidate the impact of spatial frequency on ocular growthand myopia development in children.
Changes in color and luminance contrast are also
found to provide cues for defocus and thus affect emmetropization. Higher red contrast in the defocused retinal
image than the green and blue components under simulation can relax accommodation and reduce eye growth,whereas higher contrast of the blue component compared to the green and red was found to increase accommodation and promote eye growth [109].
Near work

Among children, indoor activities primarily consist oftasks such as reading, writing, and using digital devices
at close but variable distances. When these distances areconverted into diopters (which is the reciprocal of the
distance in meters), it becomes evident that the indoor
visual environment exhibits significantly greater dioptric variations compared to outdoor settings [88]. Ocular
accommodation increases directly with the proximity ofviewed objects and is due to an increase in lens convexity (in addition to pupil constriction and convergence ofthe eyes during the accommodation reflex) with resultsin the increase of the optical power of the eye [175]. The
accommodation demand profile for even basic tasks likereading a book or viewing a computer screen fluctuatesby several diopters, even across the retina (i.e., from thecentral point of fixation (the fovea) to the peripheral
retina) [88]. When the accommodation response is considered along with this dioptric variation, outdoor environments have more uniform retinal focus than indoors
which is associated with greater levels of defocus, especially in the peripheral retina. In addition, the average
mismatch between the accommodation response anddemand (known as the accommodative lag or error)
across indoor visual scenes can be 2.88 D for reading and0.14 - 1.77 D for computer use (with superior and inferior
retinal hyperopic defocus), while it can be around 0.05 D
for outdoor tasks [88]. Briefly, accommodation is more
predominant indoors compared to outdoors which is
associated with long viewing distances, fewer variations

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

in accommodative demand, and more uniform retinal
focus [88].
More time spent indoors and close reading distancehave been associated with a higher risk of myopia
among school children [176]. Notwithstanding, it isimportant to highlight that the correlation observed
between myopia and near-work activities in studies
does not necessarily establish a cause-and-effect relationship. In fact, it is plausible that the developmentof myopia could potentially lead to children spending
more time indoors engaging in near-work activities andless time participating in outdoor activities [77].
Near vision tasks and myopia

Near work is traditionally considered as paper-based
reading and writing at close distances. Nevertheless, thelast few decades were marked by the adoption of digital devices in every aspect of human society, daily living, and activity. Several studies like the OLSM, SMS,
SAVES, and others [46, 61, 177–179] explored the association of myopia with near work using parental surveys
on activities such as school assignments, digital device
use, and watching television. Myopic children were foundto spend more time studying, reading, and writing compared to non-myopic children [46, 177]. A similar trendof additional near-work time was reported among urban
children with a higher prevalence of myopia than ruralchildren with lower myopia prevalence [177]. Children
reading more than two books per week were also foundto have three times higher risk of developing myopia thanthose reading less [179]. The intensity of near work [178],
continuous reading (>30min), and closer working distance (<30cm) were also associated with an increased riskof myopia [61]. Meta-analysis of studies across five continents found near work to be associated with a greaterrisk (OR, 1.14) of myopia, with a significant more reading
time (but not studying, watching television, or computeruse) among myopes [180]. Yet, two recent meta-analyses
found insufficient evidence of a definite risk between
myopia and digital screen time [181, 182]. Even though
the impact of digital device use (“screen time” estimatedusing a parental questionnaire) on childhood myopia
failed to find any significant association between thetwo, an increase in myopic refraction by 0.28–0.33 D was
observed for every hour spent in digital devices (smartphone and computer) [183].
Shifting away from the limitations of relying solely
on questionnaires to evaluate near work, recent studies employing more objective measurement methods
have revealed that myopic children tend to engage innear activities, specifically those closer than 20 cm, forextended durations, as determined using devices like
Clouclip [184]. Additionally, these studies have indicatedPage 10 of 22

that myopic children also utilize double the smartphonedata, indicating prolonged screen time, compared totheir non-myopic counterparts [185]. Others have foundthat only 10 min or more of 2.5 D accommodative task at
downward gaze was sufficient to stimulate axial elongation [186].
On the other hand, longitudinal studies [59, 62, 85,
187] found no association of near work or number ofbooks read in children. Outdoor activity, or lack of it,
was hypothesized to have a stronger influence on thedevelopment of myopia than near work itself and their
combined effect may be a better biomarker of myopia.
Studying the combined effect of time outdoors and nearwork on myopia, “SMS” reported a protective effect ofhigh time outdoors in children performing high levels ofnear work [57]. The follow-up study “SAVES” reported
that in young children, spending less time outdoors andengaging in high levels of near work at age 6 significantly
increased the odds of developing myopia by age 12 (OR,15.9). This risk remained elevated even for those withmoderate (OR, 7.9) or low (OR, 5.3) levels of near work.
In an older cohort, a similar trend was observed. Less
outdoor time combined with high near work at age 12
conferred an increased risk of myopia by age 17 (OR, 5.1).
However, only those who spent more time outdoors were
protected, while the risk was not significantly altered byvariations in near work (moderate: OR, 2.45; high: OR,2.27). Conversely, spending moderate to low time outdoors at baseline significantly increased the myopia risk
by over 3-fold, regardless of near-work levels [61].
Potential mechanisms of near work‑related risk of myopia

Accommodation As mentioned earlier in this section, apotential explanation to the effect of near work on myopia development is the changes in ocular accommodation status like lag (difference between accommodative
demand and response) or fluctuation (standard deviation
during sustained accommodation) [188]. Results fromstudies associating myopia and accommodative lag are
mixed with reports of both lower amplitude compared to
non-myopes [189, 190] and no association between thetwo [191]. Similarly, studies prescribing bifocals and progressive addition lenses (PALS) to reduce accommodative
lag in myopes found mixed results with both clinicallysignificant and non-significant reductions in myopia progression [192–194]. Moreover, these lenses also impose
relative peripheral myopia alongside reducing the accommodative lag, and it is not clear whether this change inperipheral refraction or the accommodation influenced
the result [195]. Likewise, accommodative micro-fluctuation is thought to increase in myopes because of anincrease in aberration and reduction in blur sensitivity

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

[196] and could generate hyperopic defocus and retinal
blur, resulting in relative form-deprivation myopia. However, the current literature does not conclusively support this evidence [197, 198]. The understanding of how
accommodation contributes to the development and progression of myopia remains elusive [195].
Relative peripheral refraction Accommodation shifts
the hyperopically defocused image (behind the retina)
during near work and focusses on the retina by the forward movement of the ciliary body and lens shape alteration [199]. Although the accommodation system works
in response to foveal image defocus (blur) during nearwork, the resultant refractive change transpires for theentire retina. While performing near tasks, although the
foveal image is pulled forward and focused on the retina,
the curved shape (prolate, flatter retina in the periphery)of the retina results in relative hyperopic defocus at the
periphery which stimulates axial elongation and consequently myopia [200]. This relative peripheral hyperopic
shift was demonstrated in several studies where the ocular shape became more prolate with accommodation andwas hypothesized to be influenced by increased tension
in the choroid [201]. Conversely, some studies found a
relative peripheral myopic shift in myopes [202] whileothers found no shift in peripheral refraction in responseto accommodative demand of up to 3 D [203]. In addition, pupil constriction associated with high-intensityof light outdoors and proximity to objects results in an
increase in depth-of-focus and consequent reductionin peripheral defocus, aberration, and image blur [204–206]. Higher-order ocular aberration, especially chromatic and spherical aberrations, are also related to axial
elongation in myopic eyes [207–209]. Overall, there is alack of consistency in the results possibly due to differences in study design and cohort of choice.
Urbanization and housing type

Myopia prevalence is associated with urban areas andhigh population density [59, 61, 67, 210–213]. In fact,
countries known for their rapid urbanization, such as
China, Singapore, and South Korea, have a high prevalence of myopia, ranging from 69 to 73% [7, 214, 215]. In
addition, housing type, housing size, and living floor wererevealed to influence myopia development [216, 217].
Myopia was more prevalent among children living (1) inapartments rather than in separate houses, (2) on higher
floors compared to those living on lower floors, and (3) inlarge dwelling spaces [217–219]. However, housing types
can be confounded by the level of education, income, andoccupation [219], as living on higher floors and larger
apartments in cities may contribute to the reduction oftime spent outdoors and an increase in near work.

Page 11 of 22

Pollution

Air pollutants such as carbon monoxide, nitrogen oxides,
and ozone are hypothesized to damage the ocular tissue,
reducing the release of DA and causing systemic inflammation, oxidative stress, retinal ischemia, and resultant
myopia [220]. Fine particulate matter ­(PM2.5) and ozone­(O3) were also found to have an additive effect on myopia development, albeit in an elderly population [221].
The association between myopia and traffic-related air
pollutants PM2.5 and nitrogen oxides was found in astudy conducted among 15,822 Taiwanese [222] children and 2727 Brazilian [223] schoolchildren. However,
it is important to note that this association is confoundedby the fact that air pollution is often prevalent in urban
areas, which are also characterized by less green spaces,
low frequency visual environment, reduced time spent
outdoors, disrupted sleep, all of which may contribute tomyopia development.
Second‑hand smoking

Earlier studies with uncontrolled confounders like age,parental education, socio-economic status, and housing
type presented conflicting associations between smoking and myopia [224–228]. The possible pharmacological causal pathway mediated via both nicotinic agonist
and antagonist was also ill-defined [229, 230]. Recently,
a large cross-sectional study on 6–8-year-old Hong Kongchildren has shown an association of second-hand smoking exposure with both the onset and progression of
myopia [231]. A small but dose-response effect of smoking was observed with an increase in 0.07 D myopia or
0.04 mm AL elongation with 10 cigarettes/day [231]. The
study was cross-sectional in design and could not prove a
causal relationship.
Seasons

It is unclear whether myopia onset and progression show
seasonal variations, potentially due to variations in total
light exposure [92]. The Correction of Myopia Evaluation
Trial (COMET) [232] found that the rate of myopia progression and axial elongation decreased during summer
and increased during winter, corresponding to individual light exposure levels [233]. Interestingly, the seasonof a child’s birth was also associated with his/her risk ofdeveloping myopia, with a clearer link especially in highmyopes. Two large-scale studies in Israel (n=276,911,
16–22 years old) [234] and the UK (n=74,459, 18–100
years old) [235] observed a higher prevalence of myopia among participants born in summer/autumn thanthose born in winter. However, there was little association between myopia risk and photoperiod. Subsequent studies in China reported different findings, i.e.,lower spherical equivalent or more myopic refraction inBiswas et al. Journal of Physiological Anthropology(2024) 43:7

children exposed to the longest photoperiod by 0.44 D(n=722, 1–3 months old) [236]. Another study (n=1222,
0–3 years old) [237] reported 0.12 D more myopic refraction in children born in winter compared to children
born in summer. This association has been hypothesized
to involve factors like perinatal light exposure, melatonin
production, birth weight, and temperature. Multiple confounding factors make it challenging to definitively establish the relationship between seasons and myopia.
Lifestyle and parental factors
Physical activity

Physical activity (PA) measured using both objective(i.e., accelerometers) and subjective (i.e., questionnaires) means was shown not to be associated with myopia development [211, 238]. Others reported PA to be
inversely correlated with myopic refractive change [239],
whereas ALSPAC [60] found PA to decrease the risk ofincident myopia when done outdoors, concluding thatthe reported PA is mainly capturing information related
to time outdoors. Recent reviews further underscore therole of increased outdoor time, rather than PA itself, incontrolling myopia progression [77, 240]. Nonetheless,promoting sports and physical activity is still beneficial
for encouraging children to spend more time outdoors,
given the protective effect of outdoor time in reducing
myopia progression [211]. Furthermore, the use of theword “sports” in questionnaires instead of PA, and its
misinterpretation as only physically demanding exercise
or games led to the categorization of outdoor cycling
and walking as leisure time activity [240]. The influenceof PA is confounded by the fact that most PA is likely tooccur outdoors and its protective effect against myopia isobserved with more active outdoor PA [77, 240].
Sleep and circadian rhythms

Circadian rhythms are internal physiological and behavioral bodily processes that follow a roughly 24-h cycle[241]. These rhythms, generated by multiple oscillators inthe body, are synchronized by the central biological clock
located in the suprachiasmatic nucleus (SCN). The dominant cue for entrainment of the SCN, and consequently
other bodily circadian rhythms in humans and othermammals, is the light/dark cycle (for review see Najjar
and Zeitzer [241]). The SCN controls the rhythmicityof the pineal gland responsible for melatonin secretion
through both photic and non-photic inputs [242, 243].
Thus, the melatonin secretion profile, more specifically,
dim light melatonin onset (DLMO) can be a reliableendogenous biomarker of the circadian phase or circadian entrainment [244]. Even though DLMO has been
linked with myopia, findings are conflicting, with evidence of both differences [245] and no differences [246]Page 12 of 22

in the DLMO phase, along with variable salivary andurinary melatonin amplitudes between different refractive groups [247]. Recently, Chakraborty and colleagues
elegantly reported that myopic children exhibit a significant DLMO phase delay (~1h) and lower aMT6s urinary
melatonin levels compared to emmetropes [248]. Since
melatonin levels are very sensitive to light [247], studies with robust methodological designs under controlled
lighting conditions are essential to establish any relationship between melatonin dysregulation and myopia development. It is also worth mentioning that experimental
work has also shown that the absence of circadian timecues (e.g., constant light or constant darkness) can disrupt ocular circadian rhythms. In young rapidly growing
eyes, this disruption often results in aberrant eye growthand failure to achieve emmetropization [249].
Sleep is under circadian and homoeostatic control andmay also contribute to ocular growth and emmetropization [250]. Myopic children have recently been reported
to exhibit delays in sleep onset and wake-up time, whichaligns with delays in DLMO [248], in addition to reduced
sleep quality [248, 251] compared to emmetropes. Furthermore, it has been postulated that lack of sleep or later
bedtime could lead to additional near work, and thus
higher risk for myopia [252]. To date, however, associations between sleep disorders (e.g., insufficient duration,
poor quality, irregular, and late timing of sleep) and theincidence and progression of myopia remain deficient[253]. This is because most studies were limited by insensitive outcome measures, differences in the definition ofstudied variables and participant demographics [253], thelack of cycloplegic refraction leading to overestimation of
myopia, and recall bias from questionnaires estimating
sleep characteristics [254].
In summary, the current body of evidence seeking toestablish associations between sleep, circadian rhythms,
and myopia still demonstrates a lack of robustness. To
strengthen the validity of these findings, it is imperative
to conduct further longitudinal studies that adhere to
universally accepted definitions of sleep quality and myopia. Additionally, the incorporation of objective measures
for assessing sleep, light exposure, and near work is crucial for accurately confirming any associations between
sleep, circadian rhythms, and myopia [252, 254].
Diet and nutrition

The relationship between diet and myopia is controversial. Whole grain, higher saturated fat, refined carbohydrates, and cholesterol intake were linked with greater
axial growth and myopia [255–257]. In contrast, otherstudies found no association between the development ofchildhood myopia with vitamin A, protein, fat, and carbohydrate in diets [258–260]. As suggested earlier in theBiswas et al. Journal of Physiological Anthropology(2024) 43:7

“vitamin D” sub-section under the “Potential mechanisms
for light-induced myopia control”, vitamin D probably
offers no protection towards myopia and its blood serum
level only indicates sunlight exposure [166, 167].
In a retrospective analysis of 6855 individuals aged
12 to 25 years, no significant association with myopia
was found for nutritional factors like serum vitamin D,
glucose levels, or caffeine intake, except for increased
insulin levels, which were related to a higher likelihoodof having myopia [261]. In addition, a systematic review
revealed that most studies on nutrients and dietary associations with myopia are non-interventional and provide
inconsistent evidence of a connection [262]. Given thecomplexity of diet and nutrition, more structured investigations are necessary to fully comprehend any potential
associations with myopia.
Socioeconomic status and level of education

Socioeconomic status is defined by several factors suchas parental education, employment, income, accessibility

Page 13 of 22

of services, school fees (private vs government), andhousing type [187, 263–265]. A large-scale study in
China found a positive correlation between myopia andhigher socioeconomic status indicators such as urban living, owning property, and duration of education [266].
The authors proposed that economic development fosters a desire for wealth, leading to increased educational
pursuit and heavier academic burdens, ultimately resulting in higher myopia rates [266]. While other studies
found higher socioeconomic status to be associated withmyopia [264, 265, 267, 268], some failed to find any such
association [61, 187, 269]. The conflicting evidence onsocioeconomic status and myopia may stem from variations in the definition and classification of socioeconomic
status, as well as unmeasurable factors like parental
involvement and academic pressure. More importantly,
the effect of socioeconomic status can be due to morenear time and less time outdoors.
As previously discussed in the “Near visual task andmyopia” section, intensive near work, its duration, andTable 1 Summary of environmental and lifestyle factors influencing myopia
FactorEvidence Relationship with myopia

Time spent outdoors

Strong• Increasing time outdoors is associated with less risk of myopia onset.
• Dose-dependent effect.

Light intensity or light levels

Strong• Higher levels of light are associated with less myopia.
• Potentially a dose-dependent effect.

Spectral composition of light

Possible• Interventions using red, blue, or violet lights have shown promising results.
• These findings require further evaluation with a longer study duration, better side-effectevaluation, and possible rebound effect investigation.

Timing, duration, pattern of light exposure

Possible• Protective, duration-dependent effect of high illuminance light.
• The impacts of timing and patterns of light exposure are understudied in humans and lim‑
ited to animal studies.

Spatial frequency of the visual environment Possible• Lower spatial frequency is associated with an increased risk of myopia development.
• Findings are limited to animal studies and mathematical modeling in humans.

Physical activity

Weak• Not an independent factor but rather linked to time spent outdoors.

Near work

Strong• Intensity, continuity, and closer working distance are consistently associated with a higher
risk of myopia.

Accommodation

Possible• Inconsistent evidence on accommodation lag and amplitude.
• Impacts are not fully understood.

Relative peripheral refraction

Possible• Peripheral retinal hyperopic defocus is associated with myopia development.
• These findings lack consistency.

Urbanization and housing

Weak• Inconsistent and related to increased near work and reduced time spent outdoors.

Socioeconomic status

Weak• Inconsistent and related to increased near work.

Education level

Possible• Predominantly related to increased near work.

Pollution

Weak• Related to urbanization and housing type and increased near work.

Second-hand smoking

Weak• Inconsistent and weak association between smoking and myopia.
• Confounded by education and subjective measurements.

Seasons

Weak• Children born in summer have a lower incidence of myopia.
• Less myopia progression was observed during summer.
• Unclear link, confounded by multiple factors.

Sleep and circadian rhythms

Possible• Potential link between delayed circadian phase and myopia.
• Inconsistent and conflicting evidence which needs objective quantification of sleep
and light exposure.

Diet and nutrition

Weak• Inconsistent and needs more structured investigations.

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

close working distances have been linked to an increased
risk of myopia and AL elongation. Consequently, thelevel of education (measured as years of education) is
also a risk factor for myopia [270–272]. Even higher intelligence quotient and better school performance wereobserved to be positively associated with myopia [273–275]. Recent studies suggested that not only does thechild’s educational level affect their ocular development
and growth, but parental educational levels can also be asignificant risk factor for the development of myopia inchildren [276]. However, it is important to note that thisrelationship is confounded by factors like parental myopia (genetics), income, and occupation, reduced time
outdoors [277].
Myopia is a multifactorial and complex condition
affected by several environmental factors in isolationor combination. The summary of evidence from the literature on the environmental factors influencing myopia,
the quality of evidence, and their relationship with myopia documented so far is listed in Table 1.

Current treatment options for myopia control
While the refinement of environmental features and lifestyle remains the best approach for preventing or delaying the onset of myopia, today, a variety of optical andpharmacological treatment options are available to slow
the progression of myopia. These include optical interventions using multifocal contact lenses, myopia control
spectacles using defocus incorporated multiple segments,
orthokeratology, and pharmaceutical intervention using a
low-dose atropine [278, 279].
Conclusions
While genetics certainly play a role in the development of
myopia, it is crucial to recognize the substantial impact ofboth the visual and non-visual environments in shaping
its progression. The time spent outdoors and engagementin near-work activities stand out as the most influential,
independent, determinants of myopia, with contrasting
effects—the former protective, the latter exacerbating
the condition. However, our understanding of the intricate relationship between various light attributes, visualenvironments, and myopia remains limited—further
studies need to be undertaken. Similarly, the association between lifestyle factors like sleep and nutrition andmyopia remains a topic of debate, also warranting further
investigation. To effectively address childhood myopia,
we must understand the complex interplay between outdoor activities, near visual tasks, and other environmental and lifestyle factors. This holistic approach will enable
the development of tailored protective strategies including the refinement of the indoor environment (lighting,spatial frequency, etc.) for myopia prevention.

Page 14 of 22

Abbreviations
AL	Axial lengthD	Diopter
OCT	Optical coherence tomography
RPE	Retinal pigment epithelium
EDI	Enhanced depth imaging
FDM	Form deprivation myopia
GWAS	Genome-wide association studies
SNP	Single nucleotide polymorphism
SMS	Sydney myopia study
SCORM	Singapore Cohort of Risk factors for Myopia
BMPS	Beijing Myopia Progression StudyALSPAC	Avon Longitudinal Study of Parents and Children
SAVES	Sydney Adolescent Vascular and Eye Study
CLEERE	Collaborative Longitudinal Evaluation of Ethnicity and Race
OLSM	Orinda Longitudinal Study of Myopia
RCT​	Randomized controlled trial
ACES	Anyang Childhood Eye Study
COVID	Coronavirus disease
CT	Choroidal thickness
LED	Light-emitting diodes
UV	UltravioletIR	Infrared
DA	Dopamine
HT	Hydroxytryptamine
GABA	Gamma-aminobutyric acidRA	Retinoic acid
ipRGC​	Intrinsically photosensitive retinal ganglion cell
PALS	Progressive addition lenses
COMET	Correction of Myopia Evaluation Trial
PM	Particulate matter
O3	Ozone
PA	Physical activity
SCN	Suprachiasmatic nucleus
DIMS	Defocus incorporated multiple segments
ATOM	Atropine for the Treatment of Childhood Myopia
LAMP	Low concentration atropine for myopia progression
SCN	Suprachiasmatic nucleus
DLMO	Dim-light melatonin onset
Acknowledgements
None
Authors’ contributions
Conception, RPN; design of the work, RPN and SB; acquisition, SB, AEK, andMQ; analysis, SB, AEK, and MQ; interpretation of data, SB, AEK, MQ, DMXL,
SCH, JL, SMS, and RPN; drafted the work or substantively revised it, SB, AEK,
MQ, DMXL, SCH, JL, SMS, and RPN. All authors read and approved the final
manuscript.
Funding
This work was supported by the ASPIRE-NUS startup grant (NUH‑
SRO/2022/038/Startup/08) and the National Research Foundation grant(NRF2022-THE004-0002) to RPN. SB was supported by a research grantfrom the Singapore Government (IAF), Industry Collaboration Project Grant(I1901E0038), and Johnson & Johnson Vision Care to RPN. The funding organi‑zation has no role in the design, conduct, and interpretation of the research.
Availability of data and materials
Data will be made available upon reasonable request to the corresponding
author.

Declarations
Ethics approval and consent to participate
Not applicable.
Consent for publication
Not applicable.

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

Competing interests
The authors declare that they have no competing interests.
Author details
1
School of Optometry, College of Health and Life Sciences, Aston University,
Birmingham, UK. 2 Faculty of Medical Sciences, Lebanese University, Hadath,
Lebanon. 3 National University Hospital, Singapore, Singapore. 4 Departmentof Ophthalmology, Yong Loo Lin School of Medicine, National Universityof Singapore, Singapore, Singapore. 5 Singapore Eye Research Institute,Singapore, Singapore. 6 Ophthalmology and Visual Science Academic Clinical
Program, Duke-NUS Medical School, Singapore, Singapore. 7 Saw Swee HockSchool of Public Health, National University of Singapore, Singapore, Singa‑
pore. 8 Department of Biomedical Engineering, College of Design and Engi‑
neering, National University of Singapore, Singapore, Singapore.
Received: 23 October 2023 Accepted: 5 January 2024

References
1. Baird PN, Saw SM, Lanca C, Guggenheim JA, Smith Iii EL, Zhou X, et al.
Myopia. Nat Rev Dis Primers. 2020;6(1):99. https://​doi.​org/​10.​1038/​
s41572-​020-​00231-4.
2. Morgan IG, Ohno-Matsui K, Saw SM. Myopia. Lancet.
2012;379(9827):1739–48. https://​doi.​org/​10.​1016/​S0140-​6736(12)​60272-4.
3. Ohno-Matsui K, Wu PC, Yamashiro K, Vutipongsatorn K, Fang Y,
Cheung CMG, et al. IMI pathologic myopia. Invest Ophthalmol Vis Sci.
2021;62(5):5. https://​doi.​org/​10.​1167/​iovs.​62.5.5.
4. Atchison DA, Smith G, Smith G. Optics of the human eye. ButterworthHeinemann Oxford; 2000.
5. Rabbetts RB, Bennett AG. Clinical visual optics. In: Edinburgh. Elsevier/
Butterworth Heinemann; 2007.
6. Flitcroft DI, He M, Jonas JB, Jong M, Naidoo K, Ohno-Matsui K, et al. IMI defining and classifying myopia: a proposed set of standards for clinicaland epidemiologic studies. Invest Ophthalmol Vis Sci. 2019;60(3):M20–
m30. https://​doi.​org/​10.​1167/​iovs.​18-​25957.
7. Grzybowski A, Kanclerz P, Tsubota K, Lanca C, Saw SM. A review on theepidemiology of myopia in school children worldwide. BMC Ophthal‑mol. 2020;20(1):27. https://​doi.​org/​10.​1186/​s12886-​019-​1220-0.
8. Matsumura S, Ching-Yu C, Saw S-M. Global epidemiology of myopia.
Updates on Myopia. Springer: Singapore; 2020. p. 27–51.
9. Sankaridurg P, Tahhan N, Kandel H, Naduvilath T, Zou H, Frick KD, et al.
IMI impact of myopia. Invest Ophthalmol Vis Sci. 2021;62(5):2. https://​doi.​org/​10.​1167/​iovs.​62.5.2.
10. Dong L, Kang YK, Li Y, Wei WB, Jonas JB. Prevalence and time trends ofmyopia in children and adolescents in China: a systemic review andmeta-analysis. Retina (Philadelphia, Pa). 2020;40(3):399–411. https://​doi.​
org/​10.​1097/​iae.​00000​00000​002590.
11. Agarwal D, Saxena R, Gupta V, Mani K, Dhiman R, Bhardawaj A, et al.
Prevalence of myopia in Indian school children: meta-analysis of last
four decades. PLoS One. 2020;15(10):e0240750. https://​doi.​org/​10.​1371/​
journ​al.​pone.​02407​50.
12. Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, et al.
Global prevalence of myopia and high myopia and temporal trends
from 2000 through 2050. Ophthalmol. 2016;123(5):1036–42. https://​doi.​
org/​10.​1016/j.​ophtha.​2016.​01.​006.
13. Williams KM, Bertelsen G, Cumberland P, Wolfram C, Verhoeven VJ,
Anastasopoulos E, et al. Increasing prevalence of myopia in Europe andthe impact of education. Ophthalmol. 2015;122(7):1489–97. https://​doi.​
org/​10.​1016/j.​ophtha.​2015.​03.​018.
14. Schuster AK, Krause L, Kuchenbäcker C, Prütz F, Elflein HM, Pfeiffer N,
et al. Prevalence and time trends in myopia among children and ado‑lescents. Deutsches Arzteblatt int. 2020;117(50):855–60. https://​doi.​org/​
10.​3238/​arzte​bl.​2020.​0855.
15. Morgan IG, French AN, Ashby RS, Guo X, Ding X, He M, et al. The
epidemics of myopia: aetiology and prevention. Prog Retin Eye Res.
2018;62:134–49. https://​doi.​org/​10.​1016/j.​prete​yeres.​2017.​09.​004.

Page 15 of 22

16. Haarman AEG, Enthoven CA, Tideman JWL, Tedja MS, Verhoeven VJM,
Klaver CCW. The complications of myopia: a review and meta-analysis.
Invest Ophthalmol Vis Sci. 2020;61(4):49. https://​doi.​org/​10.​1167/​iovs.​
61.4.​49.
17. Wolffsohn JS, Kollbaum PS, Berntsen DA, Atchison DA, Benavente A,
Bradley A, et al. IMI - clinical myopia control trials and instrumentation
report. Invest Ophthalmol Vis Sci. 2019;60(3):M132–m60. https://​doi.​
org/​10.​1167/​iovs.​18-​25955.
18. Mutti DO, Hayes JR, Mitchell GL, Jones LA, Moeschberger ML, CotterSA, et al. Refractive error, axial length, and relative peripheral refractive
error before and after the onset of myopia. Invest Ophthalmol Vis Sci.
2007;48(6):2510–9. https://​doi.​org/​10.​1167/​iovs.​06-​0562.
19. Gaurisankar ZS, van Rijn GA, Lima JEE, Ilgenfritz AP, Cheng Y, Haasnoot
GW, et al. Correlations between ocular biometrics and refractive error: asystematic review and meta-analysis. Acta Ophthalmol. 2019;97(8):735–
43. https://​doi.​org/​10.​1111/​aos.​14208.
20. AlMahmoud T, Priest D, Munger R, Jackson WB. Correlation between
refractive error, corneal power, and thickness in a large population witha wide range of ametropia. Invest Ophthalmol Vis Sci. 2011;52(3):1235–
42. https://​doi.​org/​10.​1167/​iovs.​10-​5449.
21. Park HY, Shin HY, Park CK. Imaging the posterior segment of theeye using swept-source optical coherence tomography in myopic
glaucoma eyes: comparison with enhanced-depth imaging. Am j oph‑
thalmol. 2014;157(3):550–7. https://​doi.​org/​10.​1016/j.​ajo.​2013.​11.​008.
22. Maruko I, Iida T, Sugano Y, Oyamada H, Akiba M, Sekiryu T. Morpho‑
logic analysis in pathologic myopia using high-penetration opticalcoherence tomography. Invest Ophthalmol Vis Sci. 2012;53(7):3834–8.
https://​doi.​org/​10.​1167/​iovs.​12-​9811.
23. Park UC, Lee EK, Kim BH, Oh BL. Decreased choroidal and scleral
thicknesses in highly myopic eyes with posterior staphyloma. Sci Rep.
2021;11(1):7987. https://​doi.​org/​10.​1038/​s41598-​021-​87065-6.
24. Norman RE, Flanagan JG, Rausch SM, Sigal IA, Tertinegg I, Eilaghi A, et al.
Dimensions of the human sclera: thickness measurement and regionalchanges with axial length. Exp Eye Res. 2010;90(2):277–84. https://​doi.​
org/​10.​1016/j.​exer.​2009.​11.​001.
25. Marsh-Tootle WL, Norton TT. Refractive and structural measuresof lid-suture myopia in tree shrew. Invest Ophthalmol Vis Sci.
1989;30(10):2245–57.
26. Gao Q, Liu Q, Ma P, Zhong X, Wu J, Ge J. Effects of direct intravitreal
dopamine injections on the development of lid-suture induced myopia
in rabbits. Graefes Arch Clin Exp Ophthalmol. 2006;244(10):1329–35.
https://​doi.​org/​10.​1007/​s00417-​006-​0254-1.
27. McBrien NA, Norton TT. The development of experimental myopia andocular component dimensions in monocularly lid-sutured tree shrews(Tupaia belangeri). Vis Res. 1992;32(5):843–52. https://​doi.​org/​10.​1016/​
0042-​6989(92)​90027-g.
28. Qiao-Grider Y, Hung LF, Kee CS, Ramamirtham R, Smith EL 3rd. Recovery
from form-deprivation myopia in rhesus monkeys. Invest Ophthalmol
Vis Sci. 2004;45(10):3361–72. https://​doi.​org/​10.​1167/​iovs.​04-​0080.
29. Muralidharan AR, Lanca C, Biswas S, Barathi VA, Wan Yu Shermaine
L, Seang-Mei S, et al. Light and myopia: from epidemiologicalstudies to neurobiological mechanisms. Ther Adv Ophthalmol.
2021;13:25158414211059246. https://​doi.​org/​10.​1177/​25158​41421​
10592​46.
30. von Noorden GK, Lewis RA. Ocular axial length in unilateral con‑genital cataracts and blepharoptosis. Invest Ophthalmol Vis Sci.
1987;28(4):750–2.
31. Gusek-Schneider GC, Martus P. Stimulus deprivation myopia in humancongenital ptosis: a study of 95 patients. J pediat ophthalmol strabismus.
2001;38(6):340–8. https://​doi.​org/​10.​3928/​0191-​3913-​20011​101-​08.
32. Huo L, Cui D, Yang X, Wan W, Liao R, Trier K, et al. A retrospective study:
form-deprivation myopia in unilateral congenital ptosis. Clin Exp
Optom. 2012;95(4):404–9. https://​doi.​org/​10.​1111/j.​1444-​0938.​2012.​
00716.x.
33. Troilo D, Smith EL 3rd, Nickla DL, Ashby R, Tkatchenko AV, Ostrin LA,
et al. IMI - report on experimental models of emmetropization andmyopia. Invest Ophthalmol Vis Sci. 2019;60(3):M31–m88. https://​doi.​
org/​10.​1167/​iovs.​18-​25967.
34. Irving EL, Sivak JG, Callender MG. Refractive plasticity of the developing
chick eye. Ophthalmic Physiol Opt. 1992;12(4):448–56.

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

35. Schaeffel F, Glasser A, Howland HC. Accommodation, refractive error
and eye growth in chickens. Vision Res. 1988;28(5):639–57. https://​doi.​
org/​10.​1016/​0042-​6989(88)​90113-7.
36. Biswas S, Muralidharan AR, Betzler BK, Busoy JMF, Barathi VA, Tan RKY,et al. A duration-dependent interaction between high-intensity lightand unrestricted vision in the drive for myopia control. Invest Ophthal‑
mol Vis Sci. 2023;64(3):31. https://​doi.​org/​10.​1167/​iovs.​64.3.​31.
37. Mayer DL, Hansen RM, Moore BD, Kim S, Fulton AB. Cycloplegic refrac‑
tions in healthy children aged 1 through 48 months. Archiv ophthalmol.
2001;119(11):1625–8. https://​doi.​org/​10.​1001/​archo​pht.​119.​11.​1625.
38. Pennie FC, Wood IC, Olsen C, White S, Charman WN. A longitudinal
study of the biometric and refractive changes in full-term infants dur‑ing the first year of life. Vision Res. 2001;41(21):2799–810. https://​doi.​
org/​10.​1016/​s0042-​6989(01)​00169-9.
39. Mutti DO, Mitchell GL, Jones LA, Friedman NE, Frane SL, Lin WK, et al.
Axial growth and changes in lenticular and corneal power during
emmetropization in infants. Invest Ophthalmol Vis Sci. 2005;46(9):3074–
80. https://​doi.​org/​10.​1167/​iovs.​04-​1040.
40. Flitcroft DI. Emmetropisation and the aetiology of refractive errors. Eye(London, England). 2014;28(2):169–79. https://​doi.​org/​10.​1038/​eye.​2013.​276.
41. Iribarren R. Crystalline lens and refractive development. Prog Retin Eye
Res. 2015;47:86–106. https://​doi.​org/​10.​1016/j.​prete​yeres.​2015.​02.​002.
42. Zadnik K, Mutti DO, Mitchell GL, Jones LA, Burr D, Moeschberger ML. Normal eye
growth in emmetropic schoolchildren. Optom Vis Sci. 2004;81(11):819–28.
https://​doi.​org/​10.​1097/​01.​opx.​00001​45028.​53923.​67.
43. McCullough SJ, O’Donoghue L, Saunders KJ. Six year refractive
change among white children and young adults: evidence forsignificant increase in myopia among White UK children. PLoS One.
2016;11(1):e0146332. https://​doi.​org/​10.​1371/​journ​al.​pone.​01463​32.
44. Thorn F, Gwiazda J, Held R. Myopia progression is specified by a double
exponential growth function. Optom Vis Sci. 2005;82(4):286–97. https://​doi.​org/​10.​1097/​01.​opx.​00001​59370.​66540.​34.
45. Verkicharla PK, Ohno-Matsui K, Saw SM. Current and predicted demo‑
graphics of high myopia and an update of its associated pathologicalchanges. Ophthalmic Physiol Opt. 2015;35(5):465–75. https://​doi.​org/​
10.​1111/​opo.​12238.
46. Mutti DO, Mitchell GL, Moeschberger ML, Jones LA, Zadnik K. Parental
myopia, near work, school achievement, and children’s refractive error.
Invest Ophthalmol Vis Sci. 2002;43(12):3633–40.
47. Jiang X, Tarczy-Hornoch K, Cotter SA, Matsumura S, Mitchell P, Rose
KA, et al. Association of parental myopia with higher risk of myopia
among multiethnic children before school age. JAMA ophthalmol.
2020;138(5):501–9. https://​doi.​org/​10.​1001/​jamao​phtha​lmol.​2020.​0412.
48. Gwiazda J, Hyman L, Dong LM, Everett D, Norton T, Kurtz D, et al. Factors
associated with high myopia after 7 years of follow-up in the Correctionof Myopia Evaluation Trial (COMET) Cohort. Ophthalmic Epidemiol.
2007;14(4):230–7. https://​doi.​org/​10.​1080/​01658​10070​14864​59.
49. Pärssinen O, Kauppinen M. Risk factors for high myopia: a 22-year
follow-up study from childhood to adulthood. Acta Ophthalmol.
2019;97(5):510–8. https://​doi.​org/​10.​1111/​aos.​13964.
50. Fan Q, Verhoeven VJ, Wojciechowski R, Barathi VA, Hysi PG, Guggenheim
JA, et al. Meta-analysis of gene-environment-wide association scans
accounting for education level identifies additional loci for refractive
error. Nature commun. 2016;7:11008. https://​doi.​org/​10.​1038/​ncomm​s11008.
51. Hysi PG, Choquet H, Khawaja AP, Wojciechowski R, Tedja MS, Yin J,
et al. Meta-analysis of 542,934 subjects of European ancestry identifies
new genes and mechanisms predisposing to refractive error andmyopia. Nature genet. 2020;52(4):401–7. https://​doi.​org/​10.​1038/​
s41588-​020-​0599-0.
52. Verhoeven VJ, Hysi PG, Wojciechowski R, Fan Q, Guggenheim JA, Höhn
R, et al. Genome-wide meta-analyses of multiancestry cohorts identify
multiple new susceptibility loci for refractive error and myopia. Nature
genetics. 2013;45(3):314–8. https://​doi.​org/​10.​1038/​ng.​2554.
53. Baird PN, Schäche M, Dirani M. The GEnes in Myopia (GEM) study inunderstanding the aetiology of refractive errors. Prog Retin Eye Res.
2010;29(6):520–42. https://​doi.​org/​10.​1016/j.​prete​yeres.​2010.​05.​004.
54. Tedja MS, Haarman AEG, Meester-Smoor MA, Kaprio J, Mackey DA,
Guggenheim JA, et al. IMI - myopia genetics report. Invest Ophthalmol
Vis Sci. 2019;60(3):M89–m105. https://​doi.​org/​10.​1167/​iovs.​18-​25965.

Page 16 of 22

55. Morgan IG, Wu PC, Ostrin LA, Tideman JWL, Yam JC, Lan W, et al. IMI risk
factors for myopia. Invest Ophthalmol Vis Sci. 2021;62(5):3. https://​doi.​
org/​10.​1167/​iovs.​62.5.3.
56. Morgan I, Rose K. How genetic is school myopia? Prog Retin Eye Res.
2005;24(1):1–38. https://​doi.​org/​10.​1016/j.​prete​yeres.​2004.​06.​004.
57. Rose KA, Morgan IG, Ip J, Kifley A, Huynh S, Smith W, et al. Outdoor
activity reduces the prevalence of myopia in children. Ophthalmology.
2008;115(8):1279–85. https://​doi.​org/​10.​1016/j.​ophtha.​2007.​12.​019.
58. Dirani M, Tong L, Gazzard G, Zhang X, Chia A, Young TL, et al. Outdoor
activity and myopia in Singapore teenage children. British j ophthalmol.
2009;93(8):997–1000. https://​doi.​org/​10.​1136/​bjo.​2008.​150979.
59. Lin Z, Vasudevan B, Jhanji V, Mao GY, Gao TY, Wang FH, et al. Near work,
outdoor activity, and their association with refractive error. Optom Vis
Sci. 2014;91(4):376–82. https://​doi.​org/​10.​1097/​opx.​00000​00000​000219.
60. Guggenheim JA, Northstone K, McMahon G, Ness AR, Deere K,
Mattocks C, et al. Time outdoors and physical activity as predictorsof incident myopia in childhood: a prospective cohort study. Invest
Ophthalmol Vis Sci. 2012;53(6):2856–65. https://​doi.​org/​10.​1167/​iovs.​
11-​9091.
61. French AN, Morgan IG, Mitchell P, Rose KA. Risk factors for incident
myopia in Australian schoolchildren: the Sydney adolescent vascularand eye study. Ophthalmology. 2013;120(10):2100–8. https://​doi.​org/​
10.​1016/j.​ophtha.​2013.​02.​035.
62. Jones-Jordan LA, Mitchell GL, Cotter SA, Kleinstein RN, Manny RE, Mutti
DO, et al. Visual activity before and after the onset of juvenile myopia.
Invest Ophthalmol Vis Sci. 2011;52(3):1841–50. https://​doi.​org/​10.​1167/​
iovs.​09-​4997.
63. Jones LA, Sinnott LT, Mutti DO, Mitchell GL, Moeschberger ML, Zadnik
K. Parental history of myopia, sports and outdoor activities, and future
myopia. Invest Ophthalmol Vis Sci. 2007;48(8):3524–32. https://​doi.​org/​
10.​1167/​iovs.​06-​1118.
64. Rose KA, Morgan IG, Smith W, Burlutsky G, Mitchell P, Saw S-M. Myopia,
lifestyle, and schooling in students of Chinese ethnicity in Singapore
and Sydney. Archiv Ophthalmol. 2008;126(4):527–30. https://​doi.​org/​10.​
1001/​archo​pht.​126.4.​527.
65. Read SA, Vincent SJ, Tan CS, Ngo C, Collins MJ, Saw SM. Patterns of daily
outdoor light exposure in Australian and Singaporean children. Transl
Vis Sci Technol. 2018;7(3):8. https://​doi.​org/​10.​1167/​tvst.7.​3.8.
66. Jin JX, Hua WJ, Jiang X, Wu XY, Yang JW, Gao GP, et al. Effect of outdoor
activity on myopia onset and progression in school-aged children
in northeast China: the Sujiatun Eye Care Study. BMC Ophthalmol.
2015;15:73. https://​doi.​org/​10.​1186/​s12886-​015-​0052-9.
67. He M, Xiang F, Zeng Y, Mai J, Chen Q, Zhang J, et al. Effect of time spent
outdoors at school on the development of myopia among children in
China: a randomized clinical trial. Jama. 2015;314(11):1142–8. https://​doi.​org/​10.​1001/​jama.​2015.​10803.
68. Wu PC, Tsai CL, Wu HL, Yang YH, Kuo HK. Outdoor activity during class
recess reduces myopia onset and progression in school children. Oph‑thalmology. 2013;120(5):1080–5. https://​doi.​org/​10.​1016/j.​ophtha.​2012.​
11.​009.
69. Wu PC, Chen CT, Lin KK, Sun CC, Kuo CN, Huang HM, et al. Myopia
prevention and outdoor light intensity in a school-based cluster rand‑
omized trial. Ophthalmology. 2018;125(8):1239–50. https://​doi.​org/​10.​1016/j.​ophtha.​2017.​12.​011.
70. Bhandari KR, Shukla D, Mirhajianmoghadam H, Ostrin LA. Objective
measures of near viewing and light exposure in schoolchildren during
COVID-19. Optom Vis Sci. 2022;99(3):241–52. https://​doi.​org/​10.​1097/​
opx.​00000​00000​001871.
71. He X, Sankaridurg P, Wang J, Chen J, Naduvilath T, He M, et al. Time out‑
doors in reducing myopia: a school-based cluster randomized trial with
objective monitoring of outdoor time and light intensity. Ophthalmol‑ogy. 2022;129(11):1245–54. https://​doi.​org/​10.​1016/j.​ophtha.​2022.​06.​024.
72. Sherwin JC, Reacher MH, Keogh RH, Khawaja AP, Mackey DA, Foster PJ.
The association between time spent outdoors and myopia in children
and adolescents: a systematic review and meta-analysis. Ophthalmology.
2012;119(10):2141–51. https://​doi.​org/​10.​1016/j.​ophtha.​2012.​04.​020.
73. Xiong S, Sankaridurg P, Naduvilath T, Zang J, Zou H, Zhu J, et al. Timespent in outdoor activities in relation to myopia prevention andcontrol: a meta-analysis and systematic review. Acta Ophthalmol.
2017;95(6):551–66. https://​doi.​org/​10.​1111/​aos.​13403.

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

74. Cao K, Wan Y, Yusufu M, Wang N. Significance of outdoor time formyopia prevention: a systematic review and meta-analysis basedon randomized controlled trials. Ophthalmic Res. 2020;63(2):97–105.
https://​doi.​org/​10.​1159/​00050​1937.
75. Ho CL, Wu WF, Liou YM. Dose-response relationship of outdoor expo‑
sure and myopia indicators: a systematic review and meta-analysis ofvarious research methods. Int J Environ Res Public Health. 2019;16(14)https://​doi.​org/​10.​3390/​ijerp​h1614​2595.
76. Deng L, Pang Y. Effect of outdoor activities in myopia control: metaanalysis of clinical studies. Optom Vis Sci. 2019;96(4):276–82. https://​doi.​
org/​10.​1097/​OPX.​00000​00000​001357.
77. Karthikeyan SK, Ashwini DL, Priyanka M, Nayak A, Biswas S. Physicalactivity, time spent outdoors, and near work in relation to myopia
prevalence, incidence, and progression: an overview of systematic
reviews and meta-analyses. Indian J Ophthalmol. 2022;70(3):728–39.
https://​doi.​org/​10.​4103/​ijo.​IJO_​1564_​21.
78. Dhakal R, Shah R, Huntjens B, Verkicharla PK, Lawrenson JG. Time spent
outdoors as an intervention for myopia prevention and control inchildren: an overview of systematic reviews. Ophthalmic Physiol Opt.
2022;42(3):545–58. https://​doi.​org/​10.​1111/​opo.​12945.
79. Zhang X, Cheung SSL, Chan HN, Zhang Y, Wang YM, Yip BH, et al.
Myopia incidence and lifestyle changes among school children during
the COVID-19 pandemic: a population-based prospective study. British
j ophthalmol. 2022;106(12):1772–8. https://​doi.​org/​10.​1136/​bjoph​thalm​
ol-​2021-​319307.
80. Wang J, Li Y, Musch DC, Wei N, Qi X, Ding G, et al. Progression of myopia
in school-aged children after COVID-19 home confinement. JAMA
ophthalmol. 2021;139(3):293–300. https://​doi.​org/​10.​1001/​jamao​phtha​lmol.​2020.​6239.
81. Jones-Jordan LA, Sinnott LT, Cotter SA, Kleinstein RN, Manny RE, Mutti
DO, et al. Time outdoors, visual activity, and myopia progression injuvenile-onset myopes. Invest Ophthalmol Vis Sci. 2012;53(11):7169–75.
https://​doi.​org/​10.​1167/​iovs.​11-​8336.
82. Li SM, Li H, Li SY, Liu LR, Kang MT, Wang YP, et al. Time outdoors andmyopia progression over 2 years in Chinese children: the anyang child‑hood eye study. Invest Ophthalmol Vis Sci. 2015;56(8):4734–40. https://​doi.​org/​10.​1167/​iovs.​14-​15474.
83. Low W, Dirani M, Gazzard G, Chan YH, Zhou HJ, Selvaraj P, et al. Family
history, near work, outdoor activity, and myopia in Singapore Chinesepreschool children. British j ophthalmol. 2010;94(8):1012–6. https://​doi.​
org/​10.​1136/​bjo.​2009.​173187.
84. Zhou Z, Ma X, Yi H, Pang X, Shi Y, Chen Q, et al. Factors underlying differ‑ent myopia prevalence between middle- and low-income provinces in
China. Ophthalmology. 2015;122(5):1060–2. https://​doi.​org/​10.​1016/j.​
ophtha.​2014.​12.​019.
85. Saw SM, Shankar A, Tan SB, Taylor H, Tan DT, Stone RA, et al. A cohort
study of incident myopia in Singaporean children. Invest Ophthalmol
Vis Sci. 2006;47(5):1839–44. https://​doi.​org/​10.​1167/​iovs.​05-​1081.
86. Lanca C, Teo A, Vivagandan A, Htoon HM, Najjar RP, Spiegel DP, et al.
The effects of different outdoor environments, sunglasses and hats onlight levels: implications for myopia prevention. Transl Vis Sci Technol.
2019;8(4):7. https://​doi.​org/​10.​1167/​tvst.8.​4.7.
87. Lingham G, Mackey DA, Lucas R, Yazar S. How does spending time
outdoors protect against myopia? A review. The British journal of oph‑
thalmology. 2020;104(5):593–9. https://​doi.​org/​10.​1136/​bjoph​thalm​
ol-​2019-​314675.
88. Flitcroft DI. The complex interactions of retinal, optical and environmen‑
tal factors in myopia aetiology. Prog Retin Eye Res. 2012;31(6):622–60.
https://​doi.​org/​10.​1016/j.​prete​yeres.​2012.​06.​004.
89. Flitcroft DI, Harb EN, Wildsoet CF. The spatial frequency content ofurban and indoor environments as a potential risk factor for myopia
development. Invest Ophthalmol Vis Sci. 2020;61(11):42. https://​doi.​
org/​10.​1167/​iovs.​61.​11.​42.
90. Stone RA, Cohen Y, McGlinn AM, Davison S, Casavant S, Shaffer J, et al.
Development of experimental myopia in chicks in a natural environ‑ment. Invest Ophthalmol Vis Sci. 2016;57(11):4779–89. https://​doi.​org/​
10.​1167/​iovs.​16-​19310.
91. Karouta C, Ashby RS. Correlation between light levels and the develop‑
ment of deprivation myopia. Invest Ophthalmol Vis Sci. 2014;56(1):299–
309. https://​doi.​org/​10.​1167/​iovs.​14-​15499.

Page 17 of 22

92. Ulaganathan S, Read SA, Collins MJ, Vincent SJ. Influence of seasons
upon personal light exposure and longitudinal axial length changes inyoung adults. Acta Ophthalmol. 2019;97(2):e256–e65. https://​doi.​org/​
10.​1111/​aos.​13904.
93. Read SA, Alonso-Caneiro D, Vincent SJ, Collins MJ. Longitudinal changes
in choroidal thickness and eye growth in childhood. Invest Ophthalmol
Vis Sci. 2015;56(5):3103–12. https://​doi.​org/​10.​1167/​iovs.​15-​16446.
94. Chakraborty R, Baranton K, Spiegel D, Lacan P, Guillon M, Barrau C, et al.
Effects of mild- and moderate-intensity illumination on short-term axial
length and choroidal thickness changes in young adults. Ophthalmic
Physiol Opt. 2022;42(4):762–72. https://​doi.​org/​10.​1111/​opo.​12988.
95. Read SA, Pieterse EC, Alonso-Caneiro D, Bormann R, Hong S, Lo CH,
et al. Daily morning light therapy is associated with an increase inchoroidal thickness in healthy young adults. Sci Rep. 2018;8(1):8200.
https://​doi.​org/​10.​1038/​s41598-​018-​26635-7.
96. Cohen Y, Iribarren R, Ben-Eli H, Massarwa A, Shama-Bakri N, Chassid O.
Light intensity in nursery schools: a possible factor in refractive devel‑
opment. Asia Pac J Ophthalmol (Phila). 2022;11(1):66–71. https://​doi.​
org/​10.​1097/​APO.​00000​00000​000474.
97. Suh YW, Ha SG, Kim SH. Effect of classroom illuminance on the develop‑
ment and progression of myopia in school children. Korean J Ophthal‑mol. 2022;36(3):194–201. https://​doi.​org/​10.​3341/​kjo.​2021.​0170.
98. Hua WJ, Jin JX, Wu XY, Yang JW, Jiang X, Gao GP, et al. Elevated light lev‑els in schools have a protective effect on myopia. Ophthalmic Physiol
Opt. 2015;35(3):252–62. https://​doi.​org/​10.​1111/​opo.​12207.
99. Ashby RS, Schaeffel F. The effect of bright light on lens compensation inchicks. Invest Ophthalmol Vis Sci. 2010;51(10):5247–53. https://​doi.​org/​
10.​1167/​iovs.​09-​4689.
100. Ashby R, Ohlendorf A, Schaeffel F. The effect of ambient illuminance on
the development of deprivation myopia in chicks. Invest Ophthalmol
Vis Sci. 2009;50(11):5348–54. https://​doi.​org/​10.​1167/​iovs.​09-​3419.
101. Smith EL 3rd, Hung LF, Huang J. Protective effects of high ambient
lighting on the development of form-deprivation myopia in rhesus
monkeys. Invest Ophthalmol Vis Sci. 2012;53(1):421–8. https://​doi.​org/​
10.​1167/​iovs.​11-​8652.
102. Zhang L, Qu X. The effects of high lighting on the development ofform-deprivation myopia in guinea pigs. Invest Ophthalmol Vis Sci.
2019;60(13):4319–27. https://​doi.​org/​10.​1167/​iovs.​18-​25258.
103. Torii H, Kurihara T, Seko Y, Negishi K, Ohnuma K, Inaba T, et al. Violet light
exposure can be a preventive strategy against myopia progression.
EBioMed. 2017;15:210–9. https://​doi.​org/​10.​1016/j.​ebiom.​2016.​12.​007.
104. Jiang X, Pardue MT, Mori K, Ikeda SI, Torii H, D’Souza S, et al. Violet light
suppresses lens-induced myopia via neuropsin (OPN5) in mice. Proc
Natl Acad Sci U S A. 2021;118(22) https://​doi.​org/​10.​1073/​pnas.​20188​
40118.
105. Mori K, Torii H, Hara Y, Hara M, Yotsukura E, Hanyuda A, et al. Effectof violet light-transmitting eyeglasses on axial elongation in myopic
children: a randomized controlled trial. J clin med. 2021;10(22) https://​doi.​org/​10.​3390/​jcm10​225462.
106. Torii H, Mori K, Okano T, Kondo S, Yang HY, Yotsukura E, et al. Shortterm exposure to violet light emitted from eyeglass frames in myopic
children: a randomized pilot clinical trial. J clin med. 2022;11(20) https://​doi.​org/​10.​3390/​jcm11​206000.
107. Thakur S, Dhakal R, Verkicharla PK. Short-term exposure to blue lightshows an inhibitory effect on axial elongation in human eyes inde‑
pendent of defocus. Invest Ophthalmol Vis Sci. 2021;62(15):22. https://​doi.​org/​10.​1167/​iovs.​62.​15.​22.
108. Schilling T, Amorim-de-Sousa A, N AW, Bahmani H, González-Méijome
JM, Fernandes P. Increase in b-wave amplitude after light stimula‑tion of the blind spot is positively correlated with the axial length of
myopic individuals. Sci Rep. 2022;12(1):4785. https://​doi.​org/​10.​1038/​
s41598-​022-​08319-5.
109. Rucker FJ. The role of luminance and chromatic cues in emmetropisa‑tion. Ophthalmic Physiol Opt. 2013;33(3):196–214. https://​doi.​org/​10.​1111/​opo.​12050.
110. Lou L, Ostrin LA. The outdoor environment affects retinal and choroidal
thickness. Ophthalmic Physiol Opt. 2023;43(3):572–83. https://​doi.​org/​
10.​1111/​opo.​13107.
111. Altinkaynak H, Ceylan E, Kartal B, Keleş S, Ekinci M, Olcaysu OO. Meas‑
urement of choroidal thickness following caffeine intake in healthy

Biswas et al. Journal of Physiological Anthropology

112.

113.

114.

115.

116.
117.
118.
119.

120.

121.

122.

123.

124.
125.
126.

127.

128.
129.

130.

(2024) 43:7

subjects. Current eye res. 2016;41(5):708–14. https://​doi.​org/​10.​3109/​
02713​683.​2015.​10201​68.
Sizmaz S, Küçükerdönmez C, Pinarci EY, Karalezli A, Canan H, Yilmaz
G. The effect of smoking on choroidal thickness measured by opticalcoherence tomography. British j ophthalmol. 2013;97(5):601–4. https://​doi.​org/​10.​1136/​bjoph​thalm​ol-​2012-​302393.
Jiang Y, Zhu Z, Tan X, Kong X, Zhong H, Zhang J, et al. Effect of repeatedlow-level red-light therapy for myopia control in children: a multicenter
randomized controlled trial. Ophthalmol. 2022;129(5):509–19. https://​doi.​org/​10.​1016/j.​ophtha.​2021.​11.​023.
Dong J, Zhu Z, Xu H, He M. Myopia control effect of repeated low-level
red-light therapy in chinese children: a randomized, double-blind,
controlled clinical trial. Ophthalmol. 2023;130(2):198–204. https://​doi.​
org/​10.​1016/j.​ophtha.​2022.​08.​024.
Tang J, Liao Y, Yan N, Dereje SB, Wang J, Luo Y, et al. Efficacy of repeatedlow-level red-light therapy for slowing the progression of childhood
myopia: a systematic review and meta-analysis. Am j ophthalmol.
2023;252:153–63. https://​doi.​org/​10.​1016/j.​ajo.​2023.​03.​036.
Liu H, Yang Y, Guo J, Peng J, Zhao P. Retinal damage after repeatedlow-level red-light laser exposure. jama ophthalmol. 2023;141(7):693–5.
https://​doi.​org/​10.​1001/​jamao​phtha​lmol.​2023.​1548.
Lin G, Taylor C, Rucker F. Effect of duration, and temporal modulation,of monochromatic light on emmetropization in chicks. Vision Res.
2020;166:12–9. https://​doi.​org/​10.​1016/j.​visres.​2019.​11.​002.
Rucker FJ, Wallman J. Cone signals for spectacle-lens compensation:differential responses to short and long wavelengths. Vision Res.
2008;48(19):1980–91. https://​doi.​org/​10.​1016/j.​visres.​2008.​06.​003.
Jiang L, Zhang S, Schaeffel F, Xiong S, Zheng Y, Zhou X, et al. Interac‑tions of chromatic and lens-induced defocus during visual control ofeye growth in guinea pigs (Cavia porcellus). Vision Res. 2014;94:24–32.
https://​doi.​org/​10.​1016/j.​visres.​2013.​10.​020.
Liu R, Qian YF, He JC, Hu M, Zhou XT, Dai JH, et al. Effects of different
monochromatic lights on refractive development and eye growth inguinea pigs. Exp Eye Res. 2011;92(6):447–53. https://​doi.​org/​10.​1016/j.​exer.​2011.​03.​003.
Wang M, Schaeffel F, Jiang B, Feldkaemper M. Effects of light of different
spectral composition on refractive development and retinal dopamine
in chicks. Invest Ophthalmol Vis Sci. 2018;59(11):4413–24. https://​doi.​
org/​10.​1167/​iovs.​18-​23880.
Zou L, Zhu X, Liu R, Ma F, Yu M, Liu H, et al. Effect of altered retinal
cones/opsins on refractive development under monochromatic lights
in guinea pigs. J Ophthalmol. 2018;2018:9197631. https://​doi.​org/​10.​1155/​2018/​91976​31.
Foulds WS, Barathi VA, Luu CD. Progressive myopia or hyperopia can be
induced in chicks and reversed by manipulation of the chromaticity ofambient light. Invest Ophthalmol Vis Sci. 2013;54(13):8004–12. https://​doi.​org/​10.​1167/​iovs.​13-​12476.
Rucker F. Monochromatic and white light and the regulation of eye
growth. Exp Eye Res. 2019;184:172–82. https://​doi.​org/​10.​1016/j.​exer.​
2019.​04.​020.
Strickland R, Landis EG, Pardue MT. Short-wavelength (violet) light
protects mice from myopia through cone signaling. Invest Ophthalmol
Vis Sci. 2020;61(2):13. https://​doi.​org/​10.​1167/​iovs.​61.2.​13.
Gawne TJ, Siegwart JT Jr, Ward AH, Norton TT. The wavelengthcomposition and temporal modulation of ambient lighting strongly
affect refractive development in young tree shrews. Exp Eye Res.
2017;155:75–84. https://​doi.​org/​10.​1016/j.​exer.​2016.​12.​004.
Smith EL 3rd, Hung LF, Arumugam B, Holden BA, Neitz M, Neitz J. Effectsof long-wavelength lighting on refractive development in infant rhesus
monkeys. Invest Ophthalmol Vis Sci. 2015;56(11):6490–500. https://​doi.​
org/​10.​1167/​iovs.​15-​17025.
Gawne TJ, Ward AH, Norton TT. Long-wavelength (red) light pro‑duces hyperopia in juvenile and adolescent tree shrews. Vision Res.
2017;140:55–65. https://​doi.​org/​10.​1016/j.​visres.​2017.​07.​011.
Ward AH, Norton TT, Huisingh CE, Gawne TJ. The hyperopic effect ofnarrow-band long-wavelength light in tree shrews increases nonlinearly with duration. Vision Res. 2018;146-147:9–17. https://​doi.​org/​10.​1016/j.​visres.​2018.​03.​006.
Liu R, Hu M, He JC, Zhou XT, Dai JH, Qu XM, et al. The effects of mono‑chromatic illumination on early eye development in rhesus monkeys.

Page 18 of 22

131.
132.

133.

134.
135.
136.

137.

138.
139.
140.

141.
142.
143.
144.
145.
146.
147.

148.

149.

150.

Invest Ophthalmol Vis Sci. 2014;55(3):1901–9. https://​doi.​org/​10.​1167/​
iovs.​13-​12276.
Gawne TJ, Ward AH, Norton TT. Juvenile tree shrews do not maintainemmetropia in narrow-band blue light. Optom Vis Sci. 2018;95(10):911–
20. https://​doi.​org/​10.​1097/​opx.​00000​00000​001283.
Muralidharan AR, Low SWY, Lee YC, Barathi VA, Saw SM, Milea D, et al.
Recovery from form-deprivation myopia in chicks is dependent upon
the fullness and correlated color temperature of the light spectrum.
Invest Ophthalmol Vis Sci. 2022;63(2):16. https://​doi.​org/​10.​1167/​iovs.​
63.2.​16.
Najjar RP, Chao De La Barca JM, Barathi VA, Ho CEH, Lock JZ, Muralid‑haran AR, et al. Ocular growth and metabolomics are dependent upon
the spectral content of ambient white light. Sci Rep. 2021;11(1):7586.
https://​doi.​org/​10.​1038/​s41598-​021-​87201-2.
Biswas S. Influence of location, season and time of day on the spectral
composition of ambient light: Investigation for application in myopia. Oph‑thalmic Physiol Opt. 2023;43(4):942–3. https://​doi.​org/​10.​1111/​opo.​13140.
Najjar RP. Opinion: tailoring the lighting environment for a healthierocular growth. Light Res Technol. 2022;54(2):100. https://​doi.​org/​10.​
1177/​14771​53522​10834​30.
Backhouse S, Collins AV, Phillips JR. Influence of periodic vs continuous
daily bright light exposure on development of experimental myopia inthe chick. Ophthalmic Physiol Opt. 2013;33(5):563–72. https://​doi.​org/​
10.​1111/​opo.​12069.
Lan W, Feldkaemper M, Schaeffel F. Intermittent episodes of bright light
suppress myopia in the chicken more than continuous bright light.
PLoS One. 2014;9(10):e110906. https://​doi.​org/​10.​1371/​journ​al.​pone.​
01109​06.
Guo SS, Sivak JG, Callender MG, Herbert KL. Effects of continuous lighton experimental refractive errors in chicks. Ophthalmic Physiol Opt.
1996;16(6):486–90.
Nickla DL, Totonelly K. Brief light exposure at night disrupts the circa‑
dian rhythms in eye growth and choroidal thickness in chicks. Exp Eye
Res. 2016;146:189–95. https://​doi.​org/​10.​1016/j.​exer.​2016.​03.​003.
Sarfare S, Yang J, Nickla DL. The effects of brief high intensity light onocular growth in chicks developing myopia vary with time of day.
Experiment Eye Res. 2020;195:108039. https://​doi.​org/​10.​1016/j.​exer.​
2020.​108039.
Rucker F, Britton S, Spatcher M, Hanowsky S. Blue light protects against
temporal frequency sensitive refractive changes. Invest Ophthalmol Vis
Sci. 2015;56(10):6121–31. https://​doi.​org/​10.​1167/​iovs.​15-​17238.
Zhou X, Pardue MT, Iuvone PM, Qu J. Dopamine signaling and myopia
development: what are the key challenges. Prog Retin Eye Res.
2017;61:60–71. https://​doi.​org/​10.​1016/j.​prete​yeres.​2017.​06.​003.
Djamgoz MB, Wagner HJ. Localization and function of dopamine in theadult vertebrate retina. Neurochem int. 1992;20(2):139–91. https://​doi.​
org/​10.​1016/​0197-​0186(92)​90166-o.
Frederick JM, Rayborn ME, Laties AM, Lam DM, Hollyfield JG. Dopamin‑
ergic neurons in the human retina. J comparat neurol. 1982;210(1):65–
79. https://​doi.​org/​10.​1002/​cne.​90210​0108.
Cohen Y, Peleg E, Belkin M, Polat U, Solomon AS. Ambient illuminance,
retinal dopamine release and refractive development in chicks. Exp Eye
Res. 2012;103:33–40. https://​doi.​org/​10.​1016/j.​exer.​2012.​08.​004.
Brainard GC, Morgan WW. Light-induced stimulation of retinal dopa‑
mine: a dose-response relationship. Brain res. 1987;424(1):199–203.
https://​doi.​org/​10.​1016/​0006-​8993(87)​91211-x.
Megaw PL, Morgan IG, Boelen MK. Dopaminergic behaviour in chicken
retina and the effect of form deprivation Australian and New Zealand.
J ophthalmol. 1997;25(Suppl 1):S76–8. https://​doi.​org/​10.​1111/j.​1442-​
9071.​1997.​tb017​64.x.
Dong CJ, McReynolds JS. Comparison of the effects of flickering andsteady light on dopamine release and horizontal cell coupling in the
mudpuppy retina. J neurophysiol. 1992;67(2):364–72. https://​doi.​org/​
10.​1152/​jn.​1992.​67.2.​364.
Huang F, Yan T, Shi F, An J, Xie R, Zheng F, et al. Activation of dopamine
D2 receptor is critical for the development of form-deprivation myopia
in the C57BL/6 mouse. Invest Ophthalmol Vis Sci. 2014;55(9):5537–44.
https://​doi.​org/​10.​1167/​iovs.​13-​13211.
Goel M, Mangel SC. Dopamine-mediated circadian and light/darkadaptive modulation of chemical and electrical synapses in the outerBiswas et al. Journal of Physiological Anthropology

151.

152.

153.

154.

155.
156.
157.

158.
159.

160.

161.

162.
163.
164.

165.

166.
167.
168.

169.

(2024) 43:7

retina. Front cell neurosci. 2021;15:647541. https://​doi.​org/​10.​3389/​
fncel.​2021.​647541.
Pérez-Fernández V, Milosavljevic N, Allen AE, Vessey KA, Jobling AI,
Fletcher EL, et al. Rod photoreceptor activation alone defines therelease of dopamine in the retina. Curr Biol. 2019;29(5):763–74.e5.
https://​doi.​org/​10.​1016/j.​cub.​2019.​01.​042.
McCarthy CS, Megaw P, Devadas M, Morgan IG. Dopaminergic agentsaffect the ability of brief periods of normal vision to prevent formdeprivation myopia. Exp Eye Res. 2007;84(1):100–7. https://​doi.​org/​10.​1016/j.​exer.​2006.​09.​018.
Iuvone PM, Tigges M, Stone RA, Lambert S, Laties AM. Effects of apo‑
morphine, a dopamine receptor agonist, on ocular refraction and axial
elongation in a primate model of myopia. Invest Ophthalmol Vis Sci.
1991;32(5):1674–7.
Sekaran S, Cunningham J, Neal MJ, Hartell NA, Djamgoz MB. Nitric oxide
release is induced by dopamine during illumination of the carp retina:
serial neurochemical control of light adaptation. Europ j neurosci.
2005;21(8):2199–208. https://​doi.​org/​10.​1111/j.​1460-​9568.​2005.​04051.x.
Feldkaemper M, Schaeffel F. An updated view on the role of dopamine
in myopia. Exp Eye Res. 2013;114:106–19. https://​doi.​org/​10.​1016/j.​exer.​
2013.​02.​007.
Carr BJ, Stell WK. Nitric Oxide (NO) Mediates the inhibition of formdeprivation myopia by atropine in chicks. Sci Rep. 2016;6(1):9. https://​doi.​org/​10.​1038/​s41598-​016-​0002-7.
Huemer KH, Zawinka C, Garhöfer G, Golestani E, Litschauer B, DornerGT, et al. Effects of dopamine on retinal and choroidal blood flow
parameters in humans. British j ophthalmol. 2007;91(9):1194–8. https://​doi.​org/​10.​1136/​bjo.​2006.​113399.
Grudzińska E, Modrzejewska M. Modern diagnostic techniques for theassessment of ocular blood flow in myopia: current state of knowledge. J
Ophthalmol. 2018;2018:4694789. https://​doi.​org/​10.​1155/​2018/​46947​89.
Kwon JW, Choi JA, La TY. Serum 25-hydroxyvitamin D level is associatedwith myopia in the Korea national health and nutrition examination
survey. Medicine. 2016;95(46):e5012. https://​doi.​org/​10.​1097/​md.​00000​
00000​005012.
Yazar S, Hewitt AW, Black LJ, McKnight CM, Mountain JA, Sherwin JC,
et al. Myopia is associated with lower vitamin D status in young adults.
Invest Ophthalmol Vis Sci. 2014;55(7):4552–9. https://​doi.​org/​10.​1167/​
iovs.​14-​14589.
Tideman JW, Polling JR, Voortman T, Jaddoe VW, Uitterlinden AG, Hof‑man A, et al. Low serum vitamin D is associated with axial length andrisk of myopia in young children. Europ j epidemiol. 2016;31(5):491–9.
https://​doi.​org/​10.​1007/​s10654-​016-​0128-8.
Mutti DO, Marks AR. Blood levels of vitamin D in teens and young
adults with myopia. Optom Vis Sci. 2011;88(3):377–82. https://​doi.​org/​
10.​1097/​OPX.​0b013​e3182​0b0385.
Choi JA, Han K, Park YM, La TY. Low serum 25-hydroxyvitamin D is
associated with myopia in Korean adolescents. Invest Ophthalmol Vis
Sci. 2014;55(4):2041–7. https://​doi.​org/​10.​1167/​iovs.​13-​12853.
Williams KM, Bentham GC, Young IS, McGinty A, McKay GJ, Hogg R, et al.
Association between myopia, ultraviolet B radiation exposure, serum
vitamin D concentrations, and genetic polymorphisms in vitamin D
metabolic pathways in a multicountry European study. JAMA ophthalmol.
2017;135(1):47–53. https://​doi.​org/​10.​1001/​jamao​phtha​lmol.​2016.​4752.
Guggenheim JA, Williams C, Northstone K, Howe LD, Tilling K, St
Pourcain B, et al. Does vitamin D mediate the protective effects of time
outdoors on myopia? Findings from a prospective birth cohort. Invest
Ophthalmol Vis Sci. 2014;55(12):8550–8. https://​doi.​org/​10.​1167/​iovs.​
14-​15839.
Pan CW, Qian DJ, Saw SM. Time outdoors, blood vitamin D status
and myopia: a review. Photochem Photobiol Sci. 2017;16(3):426–32.
https://​doi.​org/​10.​1039/​c6pp0​0292g.
Hobday R. Myopia and daylight in schools: a neglected aspect ofpublic health? Perspect pub health. 2016;136(1):50–5. https://​doi.​
org/​10.​1177/​17579​13915​576679.
Huang L, Schmid KL, Zhang J, Yang GY, Wu J, Yin XN, et al. Associa‑
tion between greater residential greenness and decreased risk ofpreschool myopia and astigmatism. Environ Res. 2021;196:110976.
https://​doi.​org/​10.​1016/j.​envres.​2021.​110976.
Dadvand P, Sunyer J, Alvarez-Pedrerol M, Dalmau-Bueno A, Esnaola M,
Gascon M, et al. Green spaces and spectacles use in schoolchildren

Page 19 of 22

170.

171.
172.

173.

174.

175.
176.

177.

178.

179.
180.

181.
182.

183.

184.

185.
186.

187.

in Barcelona. Environ Res. 2017;152:256–62. https://​doi.​org/​10.​1016/j.​
envres.​2016.​10.​026.
Zhang C, Wang C, Guo X, Xu H, Qin Z, Tao L. Effects of greenness on
myopia risk and school-level myopia prevalence among high schoolaged adolescents: cross-sectional study. JMIR pub health surveill.
2023;9:e42694. https://​doi.​org/​10.​2196/​42694.
Schmid KL, Wildsoet CF. Contrast and spatial-frequency requirements
for emmetropization in chicks. Vision Res. 1997;37(15):2011–21.
https://​doi.​org/​10.​1016/​s0042-​6989(97)​00014-x.
Tran N, Chiu S, Tian Y, Wildsoet CF. The significance of retinal image
contrast and spatial frequency composition for eye growth modula‑tion in young chicks. Vision Res. 2008;48(15):1655–62. https://​doi.​org/​
10.​1016/j.​visres.​2008.​03.​022.
Xu J, Zheng Z, Drobe B, Jiang J, Chen H. The effects of spatial
frequency on the accommodation responses of myopes and emme‑
tropes under various detection demands. Vision Res. 2015;115(PtA):1–7. https://​doi.​org/​10.​1016/j.​visres.​2015.​05.​020.
Xu J, Lu X, Zheng Z, Bao J, Singh N, Drobe B, et al. The effects ofspatial frequency on the accommodative responses of myopic andemmetropic Chinese children. Transl Vis Sci Technol. 2019;8(3):65.
https://​doi.​org/​10.​1167/​tvst.8.​3.​65.
Motlagh M, Geetha R. Physiology accommodation. StatPearls. Treas‑
ure Island (FL): StatPearls Publishing Copyright © 2022, StatPearls
Publishing LLC.; 2022.
Pärssinen O, Lassila E, Kauppinen M. Associations of children’s close
reading distance and time spent indoors with myopia, based onparental questionnaire. Children (Basel, Switzerland). 2022;9(5)https://​doi.​org/​10.​3390/​child​ren90​50632.
Saw SM, Hong RZ, Zhang MZ, Fu ZF, Ye M, Tan D, et al. Near-work
activity and myopia in rural and urban schoolchildren in China. J
pediat ophthalmol strabismus. 2001;38(3):149–55. https://​doi.​org/​10.​3928/​0191-​3913-​20010​501-​08.
Ip JM, Saw SM, Rose KA, Morgan IG, Kifley A, Wang JJ, et al. Role ofnear work in myopia: findings in a sample of Australian school chil‑dren. Invest Ophthalmol Vis Sci. 2008;49(7):2903–10. https://​doi.​org/​
10.​1167/​iovs.​07-​0804.
Saw SM, Chua WH, Hong CY, Wu HM, Chan WY, Chia KS, et al.
Nearwork in early-onset myopia. Invest Ophthalmol Vis Sci.
2002;43(2):332–9.
Huang HM, Chang DS, Wu PC. The association between near work
activities and myopia in children-a systematic review and metaanalysis. PLoS One. 2015;10(10):e0140419. https://​doi.​org/​10.​1371/​
journ​al.​pone.​01404​19.
Lanca C, Saw SM. The association between digital screen timeand myopia: a systematic review. Ophthalmic Physiol Opt.
2020;40(2):216–29. https://​doi.​org/​10.​1111/​opo.​12657.
Foreman J, Salim AT, Praveen A, Fonseka D, Ting DSW, Guang He M,
et al. Association between digital smart device use and myo‑
pia: a systematic review and meta-analysis. Lancet Digit Health.
2021;3(12):e806–e18. https://​doi.​org/​10.​1016/​S2589-​7500(21)​00135-7.
Liu S, Ye S, Xi W, Zhang X. Electronic devices and myopic refraction
among children aged 6-14 years in urban areas of Tianjin China. Oph‑thalmic Physiol Opt. 2019;39(4):282–93. https://​doi.​org/​10.​1111/​opo.​
12620.
Wen L, Cao Y, Cheng Q, Li X, Pan L, Li L, et al. Objectively measured
near work, outdoor exposure and myopia in children. British j oph‑
thalmol. 2020;104(11):1542–7. https://​doi.​org/​10.​1136/​bjoph​thalm​
ol-​2019-​315258.
McCrann S, Loughman J, Butler JS, Paudel N, Flitcroft DI. Smart‑phone use as a possible risk factor for myopia. Clin Exp Optom.
2021;104(1):35–41. https://​doi.​org/​10.​1111/​cxo.​13092.
Ghosh A, Collins MJ, Read SA, Davis BA, Chatterjee P. Axial elongation
associated with biomechanical factors during near work. Optom
Vis Sci. 2014;91(3):322–9. https://​doi.​org/​10.​1097/​opx.​00000​00000​
000166.
O’Donoghue L, Kapetanankis VV, McClelland JF, Logan NS, Owen
CG, Saunders KJ, et al. Risk factors for childhood myopia: findings
from the NICER study. Invest Ophthalmol Vis Sci. 2015;56(3):1524–30.
https://​doi.​org/​10.​1167/​iovs.​14-​15549.

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

188. Gambra E, Sawides L, Dorronsoro C, Marcos S. Accommodative lag
and fluctuations when optical aberrations are manipulated. J vis.
2009;9(6):4.1–15. https://​doi.​org/​10.​1167/9.​6.4.
189. Nakatsuka C, Hasebe S, Nonaka F, Ohtsuki H. Accommodative lag
under habitual seeing conditions: comparison between myopic andemmetropic children. Japan j ophthalmol. 2005;49(3):189–94. https://​doi.​org/​10.​1007/​s10384-​004-​0175-7.
190. Gwiazda J, Thorn F, Bauer J, Held R. Myopic children show insufficient accom‑
modative response to blur. Invest Ophthalmol Vis Sci. 1993;34(3):690–4.
191. Berntsen DA, Sinnott LT, Mutti DO, Zadnik K. Accommodative lag andjuvenile-onset myopia progression in children wearing refractive
correction. Vision Res. 2011;51(9):1039–46. https://​doi.​org/​10.​1016/j.​visres.​2011.​02.​016.
192. Fricke T, Tilia D, Tran MA, Hurairah H. Optical interventions to slow the
progression of myopia. Commun eye health. 2019;32(105):19–20.
193. Brennan NA, Toubouti YM, Cheng X, Bullimore MA. Efficacy in myopia
control. Prog Retin Eye Res. 2021;83:100923. https://​doi.​org/​10.​1016/j.​
prete​yeres.​2020.​100923.
194. Jonas JB, Ang M, Cho P, Guggenheim JA, He MG, Jong M, et al. IMI
prevention of myopia and its progression. Invest Ophthalmol Vis Sci.
2021;62(5):6. https://​doi.​org/​10.​1167/​iovs.​62.5.6.
195. Logan NS, Radhakrishnan H, Cruickshank FE, Allen PM, Bandela
PK, Davies LN, et al. IMI Accommodation and binocular vision in
myopia development and progression. Invest Ophthalmol Vis Sci.
2021;62(5):4. https://​doi.​org/​10.​1167/​iovs.​62.5.4.
196. Langaas T, Riddell PM, Svarverud E, Ystenaes AE, Langeggen I,
Bruenech JR. Variability of the accommodation response in early
onset myopia. Optom Vis Sci. 2008;85(1):37–48. https://​doi.​org/​10.​1097/​OPX.​0b013​e3181​5ed6e9.
197. Lupón N, Gispets J, Cardona G, Tàpia A, Abril H. Role of microfluctua‑
tions in accommodation: a novel approach to reduce non-accommo‑
dative noise. Int J Ophthalmol. 2019;12(4):681–4. https://​doi.​org/​10.​
18240/​ijo.​2019.​04.​25.
198. Yu H, Zeng J, Li Z, Hu Y, Cui D, Zhao W, et al. Variability of accom‑
modative microfluctuations in myopic and emmetropic juveniles
during sustained near work. Int J Environ Res Pub Health. 2022;19(12)https://​doi.​org/​10.​3390/​ijerp​h1912​7066.
199. Croft MA, Heatley G, McDonald JP, Katz A, Kaufman PL. Accommoda‑
tive movements of the lens/capsule and the strand that extends
between the posterior vitreous zonule insertion zone & the lensequator, in relation to the vitreous face and aging. Ophthalmic
Physiol Opt. 2016;36(1):21–32. https://​doi.​org/​10.​1111/​opo.​12256.
200. Matsumura S, Kuo AN, Saw SM. An update of eye shape and myopia.
Eye contact lens. 2019;45(5):279–85. https://​doi.​org/​10.​1097/​icl.​
00000​00000​000571.
201. Walker TW, Mutti DO. The effect of accommodation on ocular shape.
Optom Vis Sci. 2002;79(7):424–30. https://​doi.​org/​10.​1097/​00006​324-​
20020​7000-​00010.
202. Whatham A, Zimmermann F, Martinez A, Delgado S, de la Jara PL, Sanka‑
ridurg P, et al. Influence of accommodation on off-axis refractive errors inmyopic eyes. J vis. 2009;9(3):1–3. https://​doi.​org/​10.​1167/9.​3.​14.
203. Davies LN, Mallen EA. Influence of accommodation and refrac‑
tive status on the peripheral refractive profile. British j ophthalmol.
2009;93(9):1186–90. https://​doi.​org/​10.​1136/​bjo.​2009.​159053.
204. Castejón-Mochón JF, López-Gil N, Benito A, Artal P. Ocular wavefront aberration statistics in a normal young population. Vis Res.
2002;42(13):1611–7. https://​doi.​org/​10.​1016/​s0042-​6989(02)​00085-8.
205. Atchison DA, Charman WN, Woods RL. Subjective depth-of-focus of theeye. Optom Vis Sci. 1997;74(7):511–20. https://​doi.​org/​10.​1097/​00006​
324-​19970​7000-​00019.
206. Wang B, Ciuffreda KJ. Depth-of-focus of the human eye: theory andclinical implications. Surv ophthalmol. 2006;51(1):75–85. https://​doi.​
org/​10.​1016/j.​survo​phthal.​2005.​11.​003.
207. Wang Y, Zhao K, Jin Y, Niu Y, Zuo T. Changes of higher order aberration
with various pupil sizes in the myopic eye. J refract surg. (Thorofare, NJ:
1995). 2003;19(2 Suppl):S270–4. https://​doi.​org/​10.​3928/​1081-​597x-​
20030​302-​21.
208. Xu Y, Deng J, Zhang B, Xu X, Cheng T, Wang J, et al. Higher-order aber‑rations and their association with axial elongation in highly myopic
children and adolescents. British j ophthalmol. 2022; https://​doi.​org/​10.​1136/​bjoph​thalm​ol-​2021-​319769.

Page 20 of 22

209. Karimian F, Feizi S, Doozande A. Higher-order aberrations in myopic
eyes. J ophthal vis res. 2010;5(1):3–9.
210. Shah RL, Huang Y, Guggenheim JA, Williams C. Time outdoors at spe‑cific ages during early childhood and the risk of incident myopia. Invest
Ophthalmol Vis Sci. 2017;58(2):1158–66. https://​doi.​org/​10.​1167/​iovs.​
16-​20894.
211. Read SA, Collins MJ, Vincent SJ. Light exposure and physical activity inmyopic and emmetropic children. Optom Vis Sci. 2014;91(3):330–41.
https://​doi.​org/​10.​1097/​opx.​00000​00000​000160.
212. Wang Y, Liu L, Lu Z, Qu Y, Ren X, Wang J, et al. Rural-urban differencesin prevalence of and risk factors for refractive errors among school
children and adolescents aged 6-18 years in Dalian China. Front Pub
Health. 2022;10:917781. https://​doi.​org/​10.​3389/​fpubh.​2022.​917781.
213. Rai BB, Ashby RS, French AN, Maddess T. Rural-urban differences in myo‑pia prevalence among myopes presenting to Bhutanese retinal clinicalservices: a 3-year national study. Graefes Arch Clin Exp Ophthalmol.
2021;259(3):613–21. https://​doi.​org/​10.​1007/​s00417-​020-​04891-6.
214. Rudnicka AR, Kapetanakis VV, Wathern AK, Logan NS, Gilmartin B,
Whincup PH, et al. Global variations and time trends in the preva‑
lence of childhood myopia, a systematic review and quantitative
meta-analysis: implications for aetiology and early prevention. British j
ophthalmol. 2016;100(7):882–90. https://​doi.​org/​10.​1136/​bjoph​thalm​
ol-​2015-​307724.
215. Ding BY, Shih YF, Lin LLK, Hsiao CK, Wang IJ. Myopia among schoolchil‑dren in East Asia and Singapore. Surv ophthalmol. 2017;62(5):677–97.
https://​doi.​org/​10.​1016/j.​survo​phthal.​2017.​03.​006.
216. Ip JM, Rose KA, Morgan IG, Burlutsky G, Mitchell P. Myopia and theurban environment: findings in a sample of 12-year-old Australianschool children. Invest Ophthalmol Vis Sci. 2008;49(9):3858–63. https://​doi.​org/​10.​1167/​iovs.​07-​1451.
217. Wu X, Gao G, Jin J, Hua W, Tao L, Xu S, et al. Housing type andmyopia: the mediating role of parental myopia. BMC Ophthalmol.
2016;16(1):151. https://​doi.​org/​10.​1186/​s12886-​016-​0324-z.
218. Choi KY, Yu WY, Lam CHI, Li ZC, Chin MP, Lakshmanan Y, et al. Childhood
exposure to constricted living space: a possible environmental threat
for myopia development. Ophthalmic Physiol Opt. 2017;37(5):568–75.
https://​doi.​org/​10.​1111/​opo.​12397.
219. Wong TY, Foster PJ, Hee J, Ng TP, Tielsch JM, Chew SJ, et al. Prevalence
and risk factors for refractive errors in adult Chinese in Singapore. Invest
Ophthalmol Vis Sci. 2000;41(9):2486–94.
220. Yuan T, Zou H. Effects of air pollution on myopia: an update on
clinical evidence and biological mechanisms. Environment sci
pollut res internat. 2022;29(47):70674–85. https://​doi.​org/​10.​1007/​s11356-​022-​22764-9.
221. Ruan Z, Qian Z, Guo Y, Zhou J, Yang Y, Acharya BK, et al. Ambient fineparticulate matter and ozone higher than certain thresholds associatedwith myopia in the elderly aged 50 years and above. Environment Res.
2019;177:108581. https://​doi.​org/​10.​1016/j.​envres.​2019.​108581.
222. Wei C-C, Lin H-J, Lim Y-P, Chen C-S, Chang C-Y, Lin C-J, et al. PM2.5 andNOx exposure promote myopia: clinical evidence and experimental
proof. Environment Pollut. 2019;254:113031. https://​doi.​org/​10.​1016/j.​
envpol.​2019.​113031.
223. Dadvand P, Nieuwenhuijsen MJ, Basagaña X, Alvarez-Pedrerol M, Dal‑mau-Bueno A, Cirach M, et al. Traffic-related air pollution and spectacles
use in schoolchildren. PLOS ONE. 2017;12(4):e0167046. https://​doi.​org/​
10.​1371/​journ​al.​pone.​01670​46.
224. Chua SY, Ikram MK, Tan CS, Stone RA, Cai S, Gluckman PD, et al. Is there
a link between passive smoke exposure and early-onset myopia inpreschool Asian children? Ophthalmic Physiol Opt. 2016;36(4):370–80.
https://​doi.​org/​10.​1111/​opo.​12285.
225. Iyer JV, Low WC, Dirani M, Saw SM. Parental smoking and child‑hood refractive error: the STARS study. Eye (London, England).
2012;26(10):1324–8. https://​doi.​org/​10.​1038/​eye.​2012.​160.
226. Li L, Qi Y, Shi W, Wang Y, Liu W, Hu M. A meta-analysis for association of mater‑
nal smoking with childhood refractive error and amblyopia. J Ophthalmol.
2016;2016:8263832. https://​doi.​org/​10.​1155/​2016/​82638​32.
227. Saw SM, Chia KS, Lindstrom JM, Tan DT, Stone RA. Childhood myopia
and parental smoking. British j ophthalmol. 2004;88(7):934–7. https://​doi.​org/​10.​1136/​bjo.​2003.​033175.
228. Williams C, Suderman M, Guggenheim JA, Ellis G, Gregory S, Iles-Caven
Y, et al. Grandmothers’ smoking in pregnancy is associated with aBiswas et al. Journal of Physiological Anthropology

229.
230.

231.

232.

233.
234.
235.
236.
237.
238.

239.

240.
241.
242.
243.
244.

245.

246.

247.
248.

(2024) 43:7

reduced prevalence of early-onset myopia. Sci Rep. 2019;9(1):15413.
https://​doi.​org/​10.​1038/​s41598-​019-​51678-9.
Morgan IG. Exposure to secondhand smoke and myopia in children
aged 6 to 8 years in Hong Kong. JAMA netw open. 2023;6(5):e2312995.
https://​doi.​org/​10.​1001/​jaman​etwor​kopen.​2023.​12995.
Thomson K, Kelly T, Karouta C, Morgan I, Ashby R. Insights into themechanism by which atropine inhibits myopia: evidence againstcholinergic hyperactivity and modulation of dopamine release. British jpharmacol. 2021;178(22):4501–17. https://​doi.​org/​10.​1111/​bph.​15629.
Zhang Y, Zhang XJ, Yuan N, Zhang Y, Wang YM, Tang F, et al. Analysis ofsecondhand smoke exposure and myopia among children aged 6 to 8
years in Hong Kong. JAMA netw open. 2023;6(5):e2313006. https://​doi.​
org/​10.​1001/​jaman​etwor​kopen.​2023.​13006.
Gwiazda J, Deng L, Manny R, Norton TT. Seasonal variations in the
progression of myopia in children enrolled in the correction of myopia
evaluation trial. Invest Ophthalmol Vis Sci. 2014;55(2):752–8. https://​doi.​
org/​10.​1167/​iovs.​13-​13029.
Landis EG, Yang V, Brown DM, Pardue MT, Read SA. Dim light exposureand myopia in children. Invest Ophthalmol Vis Sci. 2018;59(12):4804–11.
https://​doi.​org/​10.​1167/​iovs.​18-​24415.
Mandel Y, Grotto I, El-Yaniv R, Belkin M, Israeli E, Polat U, et al. Seasonof birth, natural light, and myopia. Ophthalmol. 2008;115(4):686–92.
https://​doi.​org/​10.​1016/j.​ophtha.​2007.​05.​040.
McMahon G, Zayats T, Chen YP, Prashar A, Williams C, Guggenheim JA.
Season of birth, daylight hours at birth, and high myopia. Ophthalmol.
2009;116(3):468–73. https://​doi.​org/​10.​1016/j.​ophtha.​2008.​10.​004.
Deng L, Gwiazda J. Birth season, photoperiod, and infancy refraction.
Optom Vis Sci. 2011;88(3):383–7. https://​doi.​org/​10.​1097/​OPX.​0b013​
e3182​0b0517.
Ma Q, Xu W, Zhou X, Cui C, Pan CW. The relationship of season of birthwith refractive error in very young children in eastern China. PLoS One.
2014;9(6):e100472. https://​doi.​org/​10.​1371/​journ​al.​pone.​01004​72.
Lundberg K, Suhr Thykjaer A, Søgaard Hansen R, Vestergaard AH,
Jacobsen N, Goldschmidt E, et al. Physical activity and myopia in Danish
children-The CHAMPS Eye Study. Acta Ophthalmol. 2018;96(2):134–41.
https://​doi.​org/​10.​1111/​aos.​13513.
Jacobsen N, Jensen H, Goldschmidt E. Does the level of physical activ‑
ity in university students influence development and progression of
myopia?—a 2-year prospective cohort study. Investigat Ophthalmol Vis
Sci. 2008;49(4):1322–7. https://​doi.​org/​10.​1167/​iovs.​07-​1144.
Suhr Thykjaer A, Lundberg K, Grauslund J. Physical activity in relation
to development and progression of myopia - a systematic review. Acta
Ophthalmol. 2017;95(7):651–9. https://​doi.​org/​10.​1111/​aos.​13316.
Najjar RP, Zeitzer JM. Chapter 2 - anatomy and physiology of the circa‑
dian system. In: Miglis MG, editor. Sleep and Neurologic Disease. San
Diego: Academic Press; 2017. p. 29–53.
Moore RY, Klein DC. Visual pathways and the central neural control of acircadian rhythm in pineal serotonin N-acetyltransferase activity. Brainres. 1974;71(1):17–33. https://​doi.​org/​10.​1016/​0006-​8993(74)​90188-7.
Blume C, Garbazza C, Spitschan M. Effects of light on human circadianrhythms, sleep and mood. Somnologie. 2019;23(3):147–56. https://​doi.​
org/​10.​1007/​s11818-​019-​00215-x.
Pandi-Perumal SR, Smits M, Spence W, Srinivasan V, Cardinali DP, LoweAD, et al. Dim light melatonin onset (DLMO): a tool for the analysis
of circadian phase in human sleep and chronobiological disorders.
Progress neuro-psychopharmacol biolog psychiatry. 2007;31(1):1–11.
https://​doi.​org/​10.​1016/j.​pnpbp.​2006.​06.​020.
Chakraborty R, Micic G, Thorley L, Nissen TR, Lovato N, Collins MJ, et al.
Myopia, or near-sightedness, is associated with delayed melatonincircadian timing and lower melatonin output in young adult humans.
Sleep. 2021;44(3) https://​doi.​org/​10.​1093/​sleep/​zsaa2​08.
Flanagan SC, Cobice D, Richardson P, Sittlington JJ, Saunders KJ.
Elevated melatonin levels found in young myopic adults are not
attributable to a shift in circadian phase. Invest Ophthalmol Vis Sci.
2020;61(8):45. https://​doi.​org/​10.​1167/​iovs.​61.8.​45.
Hussain A, Gopalakrishnan A, Scott H, Seby C, Tang V, Ostrin L, et al. Associa‑
tions between systemic melatonin and human myopia: a systematic
review. Ophthalmic Physiol Opt. 2023; https://​doi.​org/​10.​1111/​opo.​13214.
Chakraborty R, Seby C, Scott H, Tang V, Kemps E, Anstice N, et al.
Delayed melatonin circadian timing, lower melatonin output, and sleep

Page 21 of 22

249.
250.
251.

252.

253.
254.
255.

256.
257.

258.
259.

260.
261.
262.
263.

264.

265.
266.
267.

268.

disruptions in myopic, or short-sighted, children. Sleep. 2023; https://​doi.​org/​10.​1093/​sleep/​zsad2​65.
Nickla DL. Ocular diurnal rhythms and eye growth regulation: where weare 50 years after Lauber. Experiment Eye Res. 2013;114:25–34. https://​doi.​org/​10.​1016/j.​exer.​2012.​12.​013.
Chakraborty R, Ostrin LA, Nickla DL, Iuvone PM, Pardue MT, Stone RA.
Circadian rhythms, refractive development, and myopia. Ophthalmic
Physiol Opt. 2018;38(3):217–45. https://​doi.​org/​10.​1111/​opo.​12453.
Xu S, Zong Z, Zhu Y, Zhang X, Zhang Y, Wang X, et al. Association
between sleep-wake schedules and myopia among Chinese schoolaged children and adolescents: a cross-sectional study. BMC Ophthal‑mol. 2023;23(1):135. https://​doi.​org/​10.​1186/​s12886-​023-​02874-9.
Liu XN, Naduvilath TJ, Wang J, Xiong S, He X, Xu X, et al. Sleeping
late is a risk factor for myopia development amongst school-aged
children in China. Sci Rep. 2020;10(1):17194. https://​doi.​org/​10.​1038/​
s41598-​020-​74348-7.
Liu XN, Naduvilath TJ, Sankaridurg PR. Myopia and sleep in children - asystematic review. Sleep. 2023; https://​doi.​org/​10.​1093/​sleep/​zsad1​62.
Li M, Tan CS, Xu L, Foo LL, Yap F, Sun CH, et al. Sleep patterns andmyopia among school-aged children in Singapore. Front Pub Health.
2022;10:828298. https://​doi.​org/​10.​3389/​fpubh.​2022.​828298.
Berticat C, Mamouni S, Ciais A, Villain M, Raymond M, Daien V. Probabil‑
ity of myopia in children with high refined carbohydrates consumption
in France. BMC Ophthalmol. 2020;20(1):337. https://​doi.​org/​10.​1186/​
s12886-​020-​01602-x.
Lim LS, Gazzard G, Low YL, Choo R, Tan DT, Tong L, et al. Dietaryfactors, myopia, and axial dimensions in children. Ophthalmol.
2010;117(5):993–7.e4. https://​doi.​org/​10.​1016/j.​ophtha.​2009.​10.​003.
Liu Z, Wang Q, Zhao Q, Gao F, Jin N, Wang D, et al. Association between
whole-grain intake and myopia in chinese children: a cross-sectional
epidemiological study. BMC Ophthalmol. 2023;23(1):1. https://​doi.​org/​
10.​1186/​s12886-​022-​02764-6.
Ng FJ, Mackey DA, O’Sullivan TA, Oddy WH, Yazar S. Is dietary vitamin A
associated with myopia from adolescence to young adulthood? Transl
Vis Sci Technol. 2020;9(6):29. https://​doi.​org/​10.​1167/​tvst.9.​6.​29.
Chua SY, Sabanayagam C, Tan CS, Lim LS, Toh JY, Chong YS, et al. Dietand risk of myopia in three-year-old Singapore children: the GUSTO
cohort. Clin Exp Optom. 2018;101(5):692–9. https://​doi.​org/​10.​1111/​
cxo.​12677.
Li M, Tan CS, Foo LL, Sugianto R, Toh JY, Sun CH, et al. Dietary intake andassociations with myopia in Singapore children. Ophthalmic Physiol
Opt. 2022;42(2):319–26. https://​doi.​org/​10.​1111/​opo.​12929.
Harb EN, Wildsoet CF. Nutritional factors and myopia: an analysis ofnational health and nutrition examination survey data. Optom Vis Sci.
2021;98(5):458–68. https://​doi.​org/​10.​1097/​opx.​00000​00000​001694.
Chamarty S, Gupta SK, Dhakal R, Verkicharla PK. Is there any association
between nutrition and myopia? A systematic review. Optom Vis Sci.
2023;100(7):475–85. https://​doi.​org/​10.​1097/​opx.​00000​00000​002035.
Goverdhan S, Fogarty AW, Osmond C, Lockwood A, Anderson L, Kirwan
JF. Shorter axial length and increased astigmatic refractive error areassociated with socio-economic deprivation in an adult UK cohort.
Ophthalmic Epidemiol. 2011;18(1):44–7. https://​doi.​org/​10.​3109/​09286​
586.​2010.​528853.
Saxena R, Vashist P, Tandon R, Pandey RM, Bhardawaj A, Menon V, et al.
Prevalence of myopia and its risk factors in urban school children
in Delhi: the North India Myopia Study (NIM Study). PLoS One.
2015;10(2):e0117349. https://​doi.​org/​10.​1371/​journ​al.​pone.​01173​49.
Wu LJ, You QS, Duan JL, Luo YX, Liu LJ, Li X, et al. Prevalence and associ‑ated factors of myopia in high-school students in Beijing. PLoS One.
2015;10(3):e0120764. https://​doi.​org/​10.​1371/​journ​al.​pone.​01207​64.
Ma Y, Lin S, Li L, Jia Y, Zou H. Socioeconomic mechanisms of myo‑
pia boom in China: a nationwide cross-sectional study. BMJ open.
2021;11(6):e044608. https://​doi.​org/​10.​1136/​bmjop​en-​2020-​044608.
Tideman JWL, Polling JR, Hofman A, Jaddoe VW, Mackenbach JP,
Klaver CC. Environmental factors explain socioeconomic prevalencedifferences in myopia in 6-year-old children. British j ophthalmol.
2018;102(2):243–7. https://​doi.​org/​10.​1136/​bjoph​thalm​ol-​2017-​310292.
Sapkota YD, Adhikari BN, Pokharel GP, Poudyal BK, Ellwein LB. The preva‑
lence of visual impairment in school children of upper-middle socioec‑
onomic status in Kathmandu. Ophthalmic Epidemiol. 2008;15(1):17–23.
https://​doi.​org/​10.​1080/​09286​58070​17720​11.

Biswas et al. Journal of Physiological Anthropology(2024) 43:7

269. Philipp D, Vogel M, Brandt M, Rauscher FG, Hiemisch A, Wahl S, et al.
The relationship between myopia and near work, time outdoors andsocioeconomic status in children and adolescents. BMC pub health.
2022;22(1):2058. https://​doi.​org/​10.​1186/​s12889-​022-​14377-1.
270. Nickels S, Hopf S, Pfeiffer N, Schuster AK. Myopia is associatedwith education: results from NHANES 1999-2008. PLoS One.
2019;14(1):e0211196. https://​doi.​org/​10.​1371/​journ​al.​pone.​02111​96.
271. Mountjoy E, Davies NM, Plotnikov D, Smith GD, Rodriguez S, Williams
CE, et al. Education and myopia: assessing the direction of causality bymendelian randomisation. BMJ (Clin res ed). 2018;361:k2022. https://​doi.​org/​10.​1136/​bmj.​k2022.
272. Mirshahi A, Ponto KA, Hoehn R, Zwiener I, Zeller T, Lackner K, et al. Myo‑pia and level of education: results from the Gutenberg Health Study.
Ophthalmol. 2014;121(10):2047–52. https://​doi.​org/​10.​1016/j.​ophtha.​
2014.​04.​017.
273. Saw SM, Cheng A, Fong A, Gazzard G, Tan DT, Morgan I. School grades
and myopia. Ophthalmic Physiol Opt. 2007;27(2):126–9. https://​doi.​org/​
10.​1111/j.​1475-​1313.​2006.​00455.x.
274. Saw SM, Tan SB, Fung D, Chia KS, Koh D, Tan DT, et al. IQ and theassociation with myopia in children. Invest Ophthalmol Vis Sci.
2004;45(9):2943–8. https://​doi.​org/​10.​1167/​iovs.​03-​1296.
275. Williams C, Miller LL, Gazzard G, Saw SM. A comparison of measures ofreading and intelligence as risk factors for the development of myopia
in a UK cohort of children. British j ophthalmol. 2008;92(8):1117–21.
https://​doi.​org/​10.​1136/​bjo.​2007.​128256.
276. Yam JC, Tang SM, Kam KW, Chen LJ, Yu M, Law AK, et al. High preva‑
lence of myopia in children and their parents in Hong Kong Chinese
Population: the Hong Kong Children Eye Study. Acta Ophthalmol.
2020;98(5):e639–e48. https://​doi.​org/​10.​1111/​aos.​14350.
277. Xiang F, He M, Morgan IG. The impact of parental myopia on myopia
in Chinese children: population-based evidence. Optom Vis Sci.
2012;89(10):1487–96. https://​doi.​org/​10.​1097/​OPX.​0b013​e3182​6912e0.
278. Modjtahedi BS, Abbott RL, Fong DS, Lum F, Tan D. Reducing the global
burden of myopia by delaying the onset of myopia and reducing
myopic progression in children: the academy’s task force on myopia.
Ophthalmol. 2021;128(6):816–26. https://​doi.​org/​10.​1016/j.​ophtha.​
2020.​10.​040.
279. Wildsoet CF, Chia A, Cho P, Guggenheim JA, Polling JR, Read S, et al.
IMI-interventions myopia institute: interventions for controlling
myopia onset and progression report. Invest Ophthalmol Vis Sci.
2019;60(3):M106–m31. https://​doi.​org/​10.​1167/​iovs.​18-​25958.

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