Your tears help keep the surface of your eyes moist and clear of harmful debris. Tears are produced by lacrimal glands and drain through ducts on the inner side of your eye that run to your nasal passages.

Any condition that increases tear production or interferes with tear drainage can cause a buildup of water in your eyes. You’re particularly likely to notice your eyes watering when you’re lying down since gravity can’t guide water to your tear ducts.

Keep reading to learn some of the specific reasons why your eyes may water when you lie down.

It’s typical for tears to build up more in your eyes when you’re lying down as opposed to sitting or standing upright. Health conditions that cause watery eyes or a blockage of your tear duct can also contribute to excessive tearing.

Effect of gravity

Your tear drainage system has active and passive parts.

When you blink, your muscles create negative pressure in your tear ducts. This pressure draws tears inside. The passive part comes from gravity, which guides fluid toward your ducts.

When you lie down, you lose the passive part of your tear drainage system because gravity no longer pushes your tears into your ducts. Loss of this action may cause more tear buildup in your eye.

Facial pressure

When you lie on your side, your eyes may open slightly on their own, or a pillow or bedding can push them open. This can dry out your eyes, causing you to tear up later. Shifting your position so that the area around your eye isn’t in contact with your pillow may help resolve the tearing.

Yawning

It’s common for your eyes to water when yawning. It’s thought that tearing is at least partially caused by the scrunching of the muscles around your eyes, which puts pressure on your lacrimal glands.

You’re more likely to yawn when you feel tired, especially around bedtime when you’re lying in bed.

Dry eyes

According to the National Eye Institute, nearly 16 million Americans have dry eyes.

One of the most common signs of dry eye is excessive tearing. Excessive tearing may be most noticeable when you’re lying down since gravity doesn’t help your body clear the extra fluid.

Common causes of dry eyes include:

Blocked tear duct

A blocked tear duct is the most common cause of persistent tearing in children. When you have a blocked duct, tears can’t flow out of your eye, so they build up. A

blockage often causes symptoms in one eye and can either be a complete or partial blockage.

Causes of a blocked tear duct include:

  • birth defects
  • age-related changes
  • injuries
  • infections
  • tumors

Blepharitis, pink eye, and other infections

Many types of eye infections can cause excessive tearing, such as:

  • Blepharitis. Blepharitis is the medical term for eyelid inflammation. It has various causes like infections, eyelash mites, medications, and oil gland dysfunction.
  • Pink eye. Pink eye is an eye infection characterized by inflamed blood vessels that give your eye a pink to red appearance. It can be caused by viruses or bacteria.
  • Stye. A stye is a red and painful lump near your eye caused by inflammation of a blocked gland.
  • Tear sac infection. Dacryocystitis is an infection of your lacrimal sac, a part of your tear drainage system.

Any of these conditions can potentially cause worse symptoms when you’re lying down, due to poorer drainage into your tear ducts than when you’re standing.

Ectropion

Ectropion is an outward drooping of your lower eyelid that causes excessive tearing. It can have many causes, including:

  • aging
  • injury
  • rapid and significant weight loss

Along with excessive tearing, symptoms of ectropion include:

  • dry eyes
  • irritation
  • burning
  • chronic pink eye
  • redness

It’s typical to have more tear buildup when you lie down than when you’re upright because when you’re lying down, gravity doesn’t guide fluid toward your ducts. But everybody’s eyes are different, and not everybody’s eyes water when they lie down.

Tearing often resolves itself and usually isn’t a sign of a serious medical condition in the absence of other symptoms. Signs that you should seek medical attention include:

  • Your watery eyes don’t improve.
  • You also have headaches.
  • You have tenderness around your nose.
  • You have unexplained bruising around your eyes.
  • Your eyes are red, swollen, or painful.
  • You have discharge or bleeding coming from your eyes.
  • You’re having trouble seeing or changes in your vision.

You may be able to minimize tearing when lying down by:

  • propping your head up on a pillow
  • taking steps to minimize eye dryness, like taking regular breaks from looking at screens
  • treating eye infections as soon as possible
  • using artificial tears if you have dry eyes
  • taking antihistamines for allergies
  • asking your doctor if your watery eyes could be a side effect of one of your medications

Your eyes are more prone to watering when you lie down since gravity can’t guide fluid toward your tear ducts.

Having watery eyes may not be a sign of a medical condition in the absence of other symptoms.

It’s a good idea to contact a healthcare professional if you have changes in your vision or signs of an infection, such as discharge coming from your eye.