Circadian Rhythm and Vision: Supporting Healthier Eyes From Morning to Night

When you think of your circadian rhythm, you may think it only affects your sleep cycle.  However, your circadian rhythm affects your hormones, digestion, mood, and even your eye health.

Your eyes do not operate the same way throughout the day. Your circadian rhythm may affect how your eyes function, how they heal from damage, and how they feel. This is why circadian rhythm disruption can affect your eye comfort and even your vision quality. 
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Continue reading for more information on how your circadian rhythm affects your vision and what you can do to support a healthy internal clock. 

​What is a circadian rhythm?  

Your circadian rhythm is your body's natural internal clock. Light is one of the strongest signals that helps set your circadian rhythm. Your circadian rhythm impacts your sleep-wake cycle, hormone production, energy level, metabolism, tear production, and visual clarity. 
Melatonin and cortisol play a role in your 24-hour internal clock. Melatonin promotes sleep, while cortisol promotes alertness. 

How do your eyes and vision change throughout the day?

Your eyes do not function exactly the same throughout the day. Consider the factors below.

The role of melatonin: Melatonin is produced in the evening and helps promote sleep. But it also affects eye health. Melatonin can help support normal eye pressure regulation and reduce oxidative stress in the retina. If circadian rhythm disruption occurs, decreased melatonin production may also affect eye health. 

Increased dry eyes: Tear production can also change throughout the day, which may make dry eye symptoms worse in the evening. This occurs because your tear film becomes less stable as the day progresses. Tear production also decreases in the evening. Excess screen use at night can also contribute to dry eyes. 

Visual performance may change: Your ability to see clearly may fluctuate.  For example, glare sensitivity may increase after dark, and contrast sensitivity also declines at night. 
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Circadian rhythm dysfunction and the visual connection 

Circadian rhythm dysfunction can develop when your body's internal clock is out of sync with your external world, such as your work or school schedule. For instance, circadian disruption may include very early sleepiness and early waking outside of "typical" sleep hours. This may include falling asleep at 6 p.m. and waking at 2 a.m. 

Disruption to your circadian rhythm can affect sleep quality, metabolism, and mood. It may also affect vision. Research in the journal FASEB BioAdvances indicates that circadian disruption may contribute to visual dysfunction.

Researchers continue to study the exact physiological mechanisms by which circadian rhythm disruption may impact vision. However, emerging research suggests that circadian rhythm dysfunction may be linked to worsening dry eye disease, accelerated retinal aging, and decreased resilience to oxidative damage. 
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How to support a healthy circadian rhythm

Various factors can contribute to eye problems such as lifestyle factors and genetics. However improving your sleep and natural circadian rhythm is always a positive step towards better health.

To support a healthy circadian rhythm consider the following habits:

• Don't overlook getting morning light exposure which helps regulate melatonin production. Aim for 10 or 15 minutes of morning light as soon as possible after you wake up.
• Reduce exposure to bright lights in the evening including screen brightness which can suppress melatonin and impact sleep.
• Maintain consistent sleep wake times including the weekends and on your days off, which supports your internal clock.
• Determine if eye symptoms are worsening later in the day and let your eye doctor know.

Remember, a comprehensive eye exam is one of the best ways you can protect your vision. If you would like to schedule an eye appointment with one of our eye doctors, please call our office at 508-746-8600.