How Your Body Clock May Influence Myopia
- Richard Kadri-Langford
- 13 minutes ago
- 4 min read
Myopia, or short‑sightedness, is rising rapidly around the world. Today, about 2 billion people are affected, and this number is expected to climb to nearly 5 billion by 2050. High myopia, which can lead to serious eye diseases later in life, is also becoming more common.
For years, experts have known that myopia is caused by a mix of genetics and environmental factors, such as time spent outdoors, near‑work activities, and screen use. But new research suggests another important factor may be involved: circadian rhythms—your body's natural 24‑hour biological clock.
A recent review published in Frontiers in Physiology explores how circadian rhythms may play a major role in how the eye grows and why myopia develops.
What Are Circadian Rhythms?
Circadian rhythms are the internal processes that follow a daily cycle. They help regulate:
Sleep and wake times
Hormone release
Body temperature
Metabolism
Light–dark responses
These rhythms are driven by a “master clock” in the brain, but every organ—including the eye—has its own mini‑clock too.
When these clocks run smoothly, the body functions well. But when they are disrupted—through poor sleep, irregular schedules, or artificial lighting—they can cause physical changes. Researchers are now discovering that these changes may also affect the way the eye grows.
The Eye Has Its Own Biological Clocks
According to the study, the retina, choroid, and sclera all contain molecular clocks that follow daily rhythms. These tissues are essential for healthy eye growth:
The retina detects light.
The choroid helps regulate blood flow and eye shape.
The sclera provides structure and determines eye length.
These tissues naturally change throughout the day—showing rhythmic patterns in gene expression, neurotransmitter release, and tissue behaviour.
This daily rhythm helps maintain refractive balance, meaning the eye grows at the right pace. If this balance is disrupted, the eye may elongate too quickly, leading to myopia.
How Circadian Disruption May Cause Myopia
The review suggests that several biological pathways link circadian rhythms to eye growth.
Dopamine Signalling
Dopamine in the retina helps regulate eye growth, and its release follows a daily rhythm. Low levels or irregular patterns of dopamine activity have long been associated with myopia development. Circadian disruption may disturb dopamine timing, possibly leading to abnormal eye elongation.
Melatonin Signalling
Melatonin—known as the “sleep hormone”—is also active in the eye. When melatonin cycles change because of poor sleep or excessive nighttime light exposure, this can interfere with the signals that tell the eye when to grow and when to slow down.
Light‑Dependent Retinal Pathways
Light exposure strongly influences circadian rhythms. The eye contains special cells called ipRGCs (intrinsically photosensitive retinal ganglion cells) that sense daylight and help set the body clock. These cells use melanopsin, a light‑sensitive protein. Studies show that ipRGCs and melanopsin are involved in both circadian timing and myopia development.
When children spend less time outdoors or are exposed to too much artificial light, these pathways may become disrupted.
Daily Changes in Eye Pressure
The study notes that intraocular pressure (IOP) naturally changes throughout the day. These patterns may also influence eye shape. A disturbed circadian rhythm could alter these daily cycles, contributing to eye elongation.
Environmental Factors That Influence Circadian Rhythms and Myopia
The review highlights several lifestyle and environmental elements that affect the eye’s internal clock—and may therefore influence myopia risk.
Outdoor Light Exposure
Bright natural light helps regulate circadian rhythms and stimulates dopamine release in the retina. Reduced outdoor time has long been linked to higher myopia rates in children. The study supports this connection by showing how light influences the eye’s internal clocks.
Sleep–Wake Patterns
Irregular sleep schedules, insufficient sleep, or staying up too late can disrupt melatonin release and shift circadian timing. This may influence eye growth cycles and contribute to myopia progression.
Artificial Light Exposure
Screens, LED bulbs, and indoor lighting can interfere with the natural light–dark cycle. Blue‑light‑heavy exposure at night may delay circadian signals, disturbing normal eye rhythms.
What This Means for Parents and Patients
Although more research is needed, this study strengthens advice that eye doctors already give:
Encourage plenty of outdoor time
At least 1–2 hours per day can support natural light‑based regulation.
Protect sleep routines
Consistent bedtimes and good sleep hygiene help regulate the eye’s circadian clock.
Limit bright screens at night
Reducing evening screen exposure may help prevent circadian disruption.
Follow your optometrist’s guidance
Treatments such as myopia‑control lenses, atropine, and lifestyle changes work best when used together.
By understanding how the body’s internal clocks work, families may gain new motivation to support healthy daily habits.
The study from Frontiers in Physiology shows that circadian rhythms play a much bigger role in eye development than previously understood. These daily biological cycles influence everything from dopamine release to light processing—and when they are disrupted, myopia may be more likely to develop or progress.
As research continues, this growing field may lead to new tools and strategies to protect children’s vision.
If you want to learn more about myopia management, visit our Complete Guide to Myopia Control.
The role of circadian rhythms in the pathogenesis of myopia
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