November 17, 2022

The complex relationship between our tired eyes and sleep

The complex relationship between our tired eyes and sleep
Brandon Hauer, PhD
Time Read
8
min

TL;DR: Keeping our eyes open longer with our growing screen time, means exposing those healthy tears for far too long. That last doom scroll before bed can not only keep you awake, but also lead to a poor sleep, making dry eye symptoms feel worse. 

 

This week, we’re exploring the direct connection between dry eyes and poor sleep, and how the stubborn persistence of one can make the other worse.

Do you, like me, wake up in the morning and rub your eyes, blinking hard to try re-hydrate them?

After a bad sleep the night before, do your eyes sting all afternoon?

I wouldn’t be surprised if you said yes to either of these – these types of complaints may actually be more common than you think. Approximately half of people with dry eyes suffer from poor sleep.

Dry eye symptoms and sleep are closely related. They feed off each other, with dry, itchy eyes decreasing sleep quality, and a restless night worsening dry eye symptoms. 

 

One in two people with highly symptomatic dry eye are poor sleepers

This is a widespread, and well-established issue. For instance, a recent study of 71,761 Dutch participants found that those with dry eye symptoms were more likely to have poor sleep quality.

Almost half of those with dry eye symptoms “often” or “constantly” had poor sleep quality.

Alarmingly, this proportion is similar to those with sleep apnea and osteoarthritis. These are chronic conditions well-known to cause poor sleep quality. Dry eye symptoms should therefore be seen as a serious condition affecting multiple aspects of life.

In fact, it seems like dry eye disease (DED) in particular is damaging to sleep. Patients with DED experience worse sleep quality than do patients with other irritating ocular surface diseases, such as allergic conjunctivitis and chronic conjunctivitis.

A systematic review and meta-analysis concluded that patients with DED may have “poorer sleep quality, greater daytime sleepiness, less sleep, more sleep disturbances, and increased prevalence, incidence, and severity of sleep disorders compared to non-DED patients”.

Indeed, yet another study of 3303 people in Singapore found that daytime sleepiness, short sleep duration (less than 5 hours/night), and clinical insomnia were associated with dry eye symptoms. This pattern held even after correcting for socioeconomic and medical factors.

So what’s going on here? Which is causing the other?

 

Chicken or egg?

As with other comorbid conditions, like depression and anxiety which are more likely in people with DED, the directionality of this effect is complicated.

Poor sleep quality and dry eye are bidirectionally related. Depression, pain, and eye discomfort at night can worsen sleep, while poor sleep can worsen tear film quality and exacerbate symptoms.

Even one night of sleep deprivation can produce noticeable changes in tear film quality, and reduce tear secretion. 

Similar effects have been observed in mice. Sleep deprivation decreased tear secretion, and increased corneal cell defects, sensitivity, and cell death.

Critically, however, these ocular surface changes were largely reversed following 2 weeks of rest.

The lacrimal gland, responsible for tear production, is regulated predominantly by parasympathetic (“rest and digest”) nervous system activity. 

Sleep deprivation increases sympathetic nervous system activity. The corresponding decrease in parasympathetic tone therefore impairs tear production.

Conversely, dry eye symptoms can also lead to reduced sleep quality.

Topical treatment of dry eye improved overall sleep quality in DED patients that had been recently diagnosed, but not for those with longstanding DED.

Worsened sleep quality in severe DED is better correlated with mood, rather than the clinical parameters of DED.

As such, it may be that a psychiatric factor – likely, the distress caused by DED and dry eye symptoms – could be a major possible cause of impaired sleep quality.

Eye fatigue is another common DED symptom, likely caused by photophobia and tear film instability leading to blurred vision, which can also lead to distress and worsened sleep.

 

Integrate a holistic approach: Prioritizing dry eye and sleep symptoms

In light of the above findings, it is important to address both eye and sleep issues together.

Poor sleep habits could exacerbate dry eye symptoms, while the discomfort and irritation of dry eyes can worsen sleep.

Given this complex and bidirectional relationship, we emphasize a more holistic solution that addresses the full suite of digital strain symptoms.

Umay is the first digital rest and recovery company to help patients reset the effects of screen time for better sleep and eye health.

REST combines heating and cooling technology to help users wake up and wind down in just 10 minutes a day.

We have previously explored how gentle eyelid warming can also boost sleep quality.

Hopefully after reading this newsletter, it makes a bit more sense why a poor sleep can have you rubbing your eyes all day. Or why if your eyes have felt drier than usual, perhaps you’re not sleeping as well.