Obstructive sleep apnea is a condition that causes you to stop breathing in your sleep, leading you to wake up frequently during the night in order to keep breathing.

It can contribute to some serious conditions, including type 2 diabetes and heart disease, and lead to other problems that might not seem related, such as eye problems.

You may not even know you have sleep apnea, even though the disorder leads to excessive daytime sleepiness. In fact, your first clue might be a partner telling you that you snore excessively or make snorting and gasping sounds during the night.

Other symptoms of sleep apnea include :

  • waking up frequently during the night, including to urinate
  • attention, memory, or concentration problems while awake
  • dry mouth and sore throat

And then there are the other symptoms that might not normally come to mind, like dry eye syndrome.

What is dry eye?

Dry eye syndrome, or dry eye, is a common condition in which your eyes don’t make enough tears or don’t use the tears correctly. It can lead to blurred vision, burning, redness, or a feeling of grittiness in the eyes. Nearly 16 million Americans have it.

Studies have found that up to 50 percent of people with diagnosed sleep apnea have eye conditions, running the gamut from less serious conditions such as dry eye to more serious conditions such as glaucoma or impaired vision.

The more severe the sleep apnea, the more likely you are to experience eye conditions, the researchers found.

If you’re experiencing eye dryness with symptoms of apnea, it’s a good idea to speak with a doctor about a possible sleep apnea diagnosis.

Several eye conditions are associated with sleep apnea. Sleep apnea causes problems with your breathing and the circulation of blood and oxygen in your body, which affects all of your organs, including your eyes.

Sometimes, the devices used to treat your apnea, such as continuous positive airway pressure (CPAP) machines, can also cause or worsen eye conditions.

Glaucoma

Glaucoma is the name for a group of conditions that can damage your optic nerve, sometimes resulting in vision loss and blindness. The most common form, open-angle glaucoma, creates increased pressure on the optic nerve.

Your odds of developing glaucoma are higher if you have diabetes, are Black and over age 40, or are over age 60, according to the Centers for Disease Control and Prevention (CDC).

Research indicates that Black people are six to eight times more likely to develop this condition than white people, possibly due to genetics, and that people with diabetes are twice as likely to develop glaucoma.

A review of studies found that the incidence of glaucoma was also higher in people with sleep apnea. The study authors recommend comprehensive glaucoma evaluation if you have sleep apnea.

Nonarteritic anterior ischemic optic neuropathy

This condition is caused by lack of blood flow to the optic nerve, resulting in a usually painless loss of vision to one eye. The optic nerve allows the brain and eye to communicate, while the lack of blood flow interferes with that communication.

Studies have shown that people with sleep apnea are more likely to develop the condition.

Not using a CPAP machine can also worsen the effects, leading to the involvement of the second eye, according to a recent study.

Central serous chorioretinopathy

Central serous chorioretinopathy is caused by fluid leaking from a layer of tissue under the retina, the cells in the back part of your eye that translate light into signals your brain can understand. The fluid leakage can cause you to have a dim or distorted area of sight in the center of your vision.

Some research has found a higher incidence of this condition among people with sleep apnea, while other studies haven’t found a correlation. More research is needed.

Retinal vein occlusion

Retinal vein occlusion is a blockage in one of the veins that supplies blood to the retina. It can cause you to have blurred or loss of vision, usually in just one eye, that remains or gets worse over time.

In a small 2021 study and in a 2018 study, there was an increased incidence of sleep apnea among people who also had retinal vein occlusion diagnosed.

Papilledema

Papilledema is a condition in which your optic nerve swells, usually due to pressure in your brain.

It can cause short-term changes to your vision, such as blurriness and double vision, that can lead to permanent vision loss if the underlying cause isn’t treated. Papilledema can be a complication of sleep apnea.

Floppy eyelid syndrome

Floppy eyelid syndrome causes chronic eye irritation and eyelids that are lax, rubbery, and easily turned inside out. It’s associated with sleep apnea, but researchers aren’t sure why.

Floppy eyelid syndrome is uncomfortable but can be treated by lubricating your eyes, wearing an eye shield at night, and avoiding sleeping on the eye that’s affected.

Symptoms usually get better after long-term use of CPAP, but eyelid surgery is also an option if symptoms don’t improve.

Your eyes may become dry if you use a CPAP machine or other device to help treat your sleep apnea. These devices pump air into a mask that you wear around your nose and mouth.

It’s not uncommon for the air from the devices to leak from a mask that doesn’t fit quite right, causing the air to rush toward your eyes and dry them out.

A 2020 study found that the incidence of dry eye was higher in CPAP and nasal mask therapy device users, especially in those who were female, older than 50, or had metabolic or inflammatory conditions.

A 2021 review of studies also found that the use of noninvasive ventilation machines such as CPAP machines increased the incidence of dry eye but that the health benefits far outweigh the risk of the serious health conditions associated with untreated sleep apnea.

Dry eye can be very uncomfortable, but there are plenty of things you can do to ease your symptoms.

Current treatments for dry eye symptoms include lifestyle changes, over-the-counter (OTC) and prescription artificial tears, and topicals and oral medications.

The first step to management is diagnosing and treating the underlying cause.

At-home care

Some things to try at home include:

  • nonprescription artificial tears, applied several times a day
  • eyelid cleansers
  • staying hydrated
  • blinking frequently
  • resting your eyes when they’re tired
  • wearing sunglasses

Medical treatment

If those things don’t help enough, a doctor may recommend:

Sleep apnea is a serious condition that can lead to heart attack, stroke, obesity, diabetes, and more. It’s also correlated with disorders that can affect your vision, such as glaucoma.

If you think you have sleep apnea, it’s important to get a diagnosis so that you can treat the underlying cause and any related eye disorders, such as dry eye.

If you’ve received a diagnosis of sleep apnea, it’s also recommended that you get a full evaluation from an ophthalmologist, a specialist in medical and surgical eye treatment who can diagnose any vision problems and treat them early.

Here are some common questions about the connection between sleep apnea and dry eye.

Can sleep apnea affect your eyes?

Yes. Sleep apnea or the devices used to treat it can cause your eyes to become dry. Changes to your cardiovascular system and the blood vessels and veins that supply blood and oxygen to your eyes can also cause or worsen some serious eye conditions.

Can a CPAP machine cause dry eye?

CPAP machines can also make your eyes drier, but there are ways to treat the dryness, such as OTC and prescription eye drops, a properly fitting mask, and eye shields. It’s important to keep using CPAP machines because they’re effective for treating sleep apnea.

How can you tell if you have sleep apnea?

Some common symptoms include:

  • waking up frequently during the night to breathe
  • waking up frequently to urinate
  • snorting, gasping, or snoring while sleeping
  • excessive daytime sleepiness

Sleep apnea can increase your risk of heart disease, diabetes, stroke, and heart disease. It can also affect your eyes, leading to irritation, dry eye, and other related eye conditions.

Dry eye is very common, especially among those with sleep apnea who use breathing devices at home to help them sleep.

You can treat eye irritation and dry eye at home with OTC or prescription eye drops, lifestyle changes, and changes to your CPAP mask to make it airtight. A doctor can also prescribe oral antibiotics, eye inserts, or other interventions.

It’s important to see a healthcare team as soon as possible if you think you have sleep apnea so you can begin treatment and lessen your chances of more serious related eye conditions that can threaten your vision.