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Lights Off Sleep and Myopia
While outdoor time and screen limits dominate myopia prevention discussions, emerging research reveals another critical factor: sleep. Dr Nicole Liu and Professor Padmaja Sankaridurg explore the fascinating biological connections between sleep patterns and eye development, uncovering how disrupted circadian rhythms, altered dopaminemelatonin pathways, and compromised melanopsin signalling may contribute to myopia progression.
WRITERS Dr Nicole Liu and Professor Padmaja Sankaridurg
LEARNING OBJECTIVES
On completion of this CPD activity, participants should:
1. Understand the basis and evidence linking aspects of sleep to risk of myopia development and/or progression,
2. Realise pathways and mechanisms linking sleep patterns to myopia development,
3. Be aware of practical challenges in implementing sleep-based myopia interventions, and
4. Be able to make evidence-based recommendations for incorporating sleep health education into a holistic myopia management strategy.
Light strongly affects all living beings, is intricately interlinked with circadian rhythm, and significantly influences human health. Yet even ‘light’ possesses a sinister side with exposure to light at an inappropriate time linked to many disorders.1 For example, even minimal light during sleep has been associated with multiple health disorders, including heart disease.2
Interestingly, the discussion extends to myopia as well. Reports from the late 1990s suggested that nighttime exposure to ambient lighting in infants increased the risk of myopia.3 While later studies failed to find the connection with nighttime lighting during sleep and myopia,4,5 an article published in 2002 suggested that less daily exposure to darkness was a risk factor for myopia in law students.6 This sparked a lively debate,6-8with suggestions that students with fewer hours of darkness might simply be “those who stayed up later or got up earlier and turned the lights on”.7 Thus, an intriguing connection between sleep and myopia began to take root.
More recently, a large body of work found circadian rhythms to be associated with ocular growth, and this naturally led to explorations of sleep and myopia.9-11 The role of sleep in many dimensions such as duration,12 quality,13 sleep-wake cycles,14 and variations in sleep patterns between weekdays and weekends15 was investigated for its role in myopia.
Interestingly, a 2024 meta-analysis showed that short sleep duration served as a risk factor for myopia, while long sleep duration acted as a protective factor, however Mendelian randomisation analysis found no significant causal relationship.16 Although the results are inconsistent, and much work remains to fully understand the role of sleep and myopia,17 the body of evidence suggests that sleep may be a modifiable risk factor for myopia – one that has been largely overlooked until now.
THE SLEEP-MYOPIA CONNECTION
The relationship between sleep and myopia can be attributed to three interconnected biological factors.
Circadian Rhythms High and low illumination levels, as in day versus night, are linked to circadian rhythms and regulation of many body functions. In the eyes, the retina’s intrinsic circadian clock plays a critical role in visual processing,18 and disruption of this clock leads to alterations of ocular parameters.19 The eye naturally elongates during the day and shrinks at night, but disrupted sleep interferes with this process,14 potentially contributing to the development of myopia.
Dopamine-Melatonin Pathways Dopamine and melatonin are neurotransmitters that interact to regulate circadian rhythms. Sleep deprivation downregulates dopamine levels,20 affecting eye growth and development of myopia.21
Melanopsin System Intrinsically photosensitive retinal ganglion cells (ipRGCs) containing melanopsin form synaptic connections with dopaminergic amacrine cells, creating complex signalling pathways that influence eye development.22,23 Research has shown that disruption of these pathways significantly affects refractive development and myopia susceptibility.24
CHALLENGES OF SLEEP-BASED INTERVENTIONS
While sleep represents a promising intervention target, implementing sleepfocussed myopia prevention faces several practical challenges. Modern urban lifestyles, with their emphasis on evening and late-night activities and exposure to artificial lighting, contribute to disrupted sleep-wake cycles and circadian rhythms.
In many East and South-East Asian countries, where myopia prevalence is highest, academic pressures often interfere with healthy sleep patterns.25 Students frequently forego sleep for extended study periods, creating a feedback loop wherein the heightened educational pressures driving myopia risk also reduce the preventative effects of adequate sleep that counter it.
Additionally, the increasing use of electronic devices, particularly before bedtime, compounds these challenges. Screen time delays melatonin release and disrupts sleep timing, potentially exacerbating both sleep problems and myopia risk simultaneously.26
“the body of evidence suggests that sleep may be a modifiable risk factor for myopia – one that has been largely overlooked until now”
IMPLEMENTING SLEEP-BASED INTERVENTIONS
While sleep-based myopia interventions are still emerging, and despite the challenges in implementation, healthy sleep patterns should form an integral component in comprehensive and holistic myopia management.
Targeted interventions for high-risk children can be integrated into existing eye care protocols. These interventions might involve sleep hygiene education, circadian rhythm optimisation, and family-based strategies.
PUBLIC HEALTH INTERVENTIONS
In countries with high myopia prevalence, as well in those with highly urbanised environments, public health campaigns could incorporate sleep health as a key component of myopia prevention strategies. Sleep health promotion represents a low-risk, cost-effective approach that complements existing methods. This is especially relevant in urban environments where access to outdoor spaces may be limited but where sleep habits can be modified through education and environmental changes.
CONCLUSION
Ultimately, more research is needed to optimise how we integrate sleep-based interventions into comprehensive myopia care. However, promoting healthy sleep represents a promising, low-risk approach that offers multiple health benefits beyond myopia management. The emerging evidence linking sleep duration, quality, timing, and consistency to myopia risk provides eye care practitioners with new tools for patient education and management strategies.
The relationship between sleep and myopia offers hope for addressing the global myopia epidemic through practical, achievable lifestyle modifications. By incorporating sleep health education into myopia management programmes, and recognising sleep as an essential component of eye health, we can take a more holistic approach to protecting vision while supporting overall wellbeing in children and adolescents.
Understanding the complex biological mechanisms linking circadian rhythms, dopamine pathways, and eye growth provides a scientific foundation for these recommendations. As our knowledge of these intricate systems continues to evolve, sleep-based interventions may become as fundamental to myopia care as outdoor time recommendations are today.
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References available at mieducation.com.
Eye Care Practitioners’ Role
Eye care practitioners are uniquely positioned to educate families about these connections and provide practical guidance.
Practical recommendations for parents and children include:
1. Prioritise adequate sleep duration: Follow age-specific guidelines from the American National Sleep Foundation: preschoolers (3–5 years) need 10–13 hours, school-age children (6–13 years) need 9–11 hours, teenagers (14–17 years) need 8–10 hours, and young adults (18–25 years) need 7–9 hours of sleep.27
2. Maintain consistent sleep schedules: Keep regular sleep-wake patterns, even on weekends, to support healthy circadian rhythms.
3. Optimise sleep timing: Encourage earlier bedtimes, when possible, as later bedtimes have been associated with increased myopia risk.28 This is particularly important during the school years when eye development is most active.
4. Practise good sleep hygiene: Limit screen time before bedtime, as electronic devices delay melatonin release and disrupt sleep timing. Create a sleep-conducive environment that is dark, cool, and quiet.
5. Combine with outdoor time: Spending time outdoors during the day – already a key recommendation for myopia prevention – can also improve sleep quality and circadian rhythm regulation, creating synergistic benefits for myopia prevention.29
6. Address academic pressures: Work with families to find balance between educational demands and healthy sleep patterns, recognising that adequate sleep may improve academic performance while protecting eye health.
Dr Nicole Liu is the Clinical Research Manager at ZEISS Vision Care, where she oversees clinical trials related to myopia. She completed her PhD in Optometry and Vision Science at the University of New South Wales and the Brien Holden Vision Institute, investigating the influence of circadian rhythm on the development of myopia under the supervision of Prof Sankaridurg and Associate Professor Thomas John Naduvilath.
Professor Padmaja Sankaridurg is Head of Global Myopia Management at ZEISS Vision Care and Conjoint Professor at University of New South Wales Sydney. With nearly two decades of myopia research experience, she has authored 100+ peer-reviewed publications, holds multiple patents, and lectures globally on myopia research and treatment strategies.