Pregnant woman looking through a window with tear-shaped raindrops.

Pregnancy and Your Eyes: How Hormones Affect Tear Production

Theo Raines monogram
Theo Raines in Health & Wellness October 2026 • 4 min read.

"Discover the surprising connection between pregnancy, tear osmolarity, and dry eye symptoms. Learn how hormonal changes impact your eyes and what you can do about it."


Pregnancy brings about many changes throughout a woman's body, and the eyes are no exception. While some changes are physiological, like a decrease in intraocular pressure or increased sensitivity to light, others can exacerbate existing conditions or lead to new discomforts.

One common complaint during pregnancy is dry eye. This occurs when your eyes don't produce enough tears or the tears evaporate too quickly, leading to irritation, redness, and a gritty feeling. Hormonal fluctuations, particularly changes in estrogen and androgen levels, are thought to play a significant role in this.

This article will delve into a recent study examining the effects of pregnancy on tear osmolarity, a key indicator of dry eye. By understanding how pregnancy affects tear production, we can explore ways to manage dry eye symptoms and maintain optimal eye health during this special time.

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Measuring Tear Changes

Research on pregnancy-related dry eye has measured tear osmolarity and Schirmer test values in healthy pregnant women. One study used the TearLab osmolarity system and Schirmer 1 testing on one randomly selected eye, repeating measurements in the last trimester. A clinical review summarizes epidemiological studies using different diagnostic methods and populations, underscoring that pregnancy-related dry eye assessment is not based on a single test.

From Testing to Hormonal Context

A foundational pregnancy study evaluated tear osmolarity with the TearLab system and tear function with Schirmer 1 testing, repeating the pregnant participants’ measurements during the last trimester. Later clinical discussion placed these measurements within the broader physiological context of pregnancy, including profound hormonal, metabolic, and immunological changes. The 2025 review identifies fluctuations in estrogen and progesterone as consistent factors associated with dry eye syndrome, while also noting insulin resistance and maternal immune tolerance.

What is Tear Osmolarity and Why Does It Matter During Pregnancy?

Pregnant woman looking through a window with tear-shaped raindrops.

Tear osmolarity refers to the concentration of dissolved salts and other substances in your tears. When tear osmolarity is high, it indicates that there isn't enough water in the tears, which can lead to inflammation and damage to the eye's surface. Think of it like a swimming pool: if there are too many chemicals and not enough water, it's going to irritate your skin.

The study mentioned earlier involved 60 women aged 20 to 40. Thirty women in their first trimester of pregnancy comprised the study group, while the other 30, who were not pregnant and had no other health conditions besides refractive errors, formed the control group. Researchers measured tear osmolarity and performed Schirmer tests (which measure tear production) on all participants. The pregnant women were tested again in their last trimester.

Here's what the study found:
  • First Trimester: The average tear osmolarity in the pregnant women was 304.9 mOsm/L.
  • Last Trimester: This decreased to 300.2 mOsm/L.
  • Control Group: The average tear osmolarity for the non-pregnant women was 306.3 mOsm/L.
  • Schirmer Test Results: Schirmer test results also showed a decrease in tear production in the pregnant group during their last trimester compared to the control group.
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Recent Evidence

A 2024 review reports that several, but not all, studies found relatively low tear production during pregnancy using clinical Schirmer testing. The review states that tear production appeared to recover in the immediate postpartum period, defined there as 48 to 72 hours after delivery, with a presumed sudden drop in estrogen. In a study of pregnant American Bully bitches, tear production decreased on day 60 compared with other periods but remained within the normal range for the species; separately, a sodium hyaluronate study included 60 patients, or 120 eyes, followed for three months.

When Measures Disagree

The reported tear osmolarity measurements do not show a simple pattern of worsening across pregnancy: the study group measured 304.9 ± 8.0 mOsm/L in the first trimester and 300.2 ± 7.1 mOsm/L in the last trimester, while the control group measured 306.3 ± 6.2 mOsm/L. These figures illustrate why a single physiological measurement may not capture every person’s experience of dryness. A clinical information page likewise reports that new or substantially worsened dry-eye symptoms can occur during pregnancy and describes them as changes worth addressing.

Multiple Influences on the Ocular Surface

The clinical review hypothesizes that pregnancy-related hormonal, metabolic, and immunological changes contribute significantly to ocular-surface instability. It frames these changes as factors that may trigger or exacerbate dry eye disease rather than as a single isolated cause. The review uses measures including tear break-up time, the Ocular Surface Disease Index, and the Standard Patient Evaluation of Eye Dryness to compare ocular-surface symptoms and function.

These results suggest that pregnancy does indeed impact tear osmolarity and tear production. Interestingly, tear osmolarity decreased as pregnancy progressed. While seemingly counterintuitive, this decrease might be a protective mechanism to maintain the ocular surface health.

What Does This Mean for You? Practical Tips for Managing Dry Eyes During Pregnancy

While the study suggests a potential protective mechanism, many pregnant women still experience dry eye symptoms. If you're one of them, don't worry! There are several things you can do to find relief:

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Combining Clinical Measures

The pregnancy tear study combined tear osmolarity measurement with the TearLab osmolarity system and tear-function testing with Schirmer 1. Measurements were taken from one randomly chosen eye for each participant. The same eye in pregnant participants was tested again during the last trimester, allowing within-person comparison over pregnancy.

Tracking Hormonal Effects

The article on pregnancy and eye health presents hormonal shifts as a possible explanation for changes in tear production during pregnancy. It specifically highlights pregnancy-related tear osmolarity as an area for understanding why eyes may feel drier than usual. Its focus on keeping the eyes comfortable points toward continued attention to symptom monitoring and pregnancy-appropriate eye care.

How common dry eye was in a pregnancy cohort

  • 40.8% of pregnant womenDry eye disease was identified in 82 of 201 pregnant women, corresponding to 40.8% of the cohort.[1]
  • 45 pregnant; 47 controlsA separate prospective comparison enrolled 45 healthy pregnant women and 47 age-matched non-pregnant controls.[2]

What the measurements do and do not establish

The evidence supports a changing tear environment during pregnancy, but reduced osmolarity does not by itself establish that symptoms improved or worsened.[3]

The available findings therefore connect pregnancy with altered tear function without identifying a single mechanism that explains every case.[1] [3]

How pregnancy findings compare across reports

A separate three-month report enrolled patients with dry eye syndrome and compared pregnant patients with non-pregnant patients who also had the condition.[4]

Later clinical discussion describes lower tear production in several pregnancy studies, with recovery reported in the immediate postpartum period, although the cited review notes that not every study found the same pattern.[3]

What remains unresolved about pregnancy and tears

  • Why tear osmolarity falls as pregnancy advances, despite the expectation that dry eye disease is associated with higher osmolarity, remains unclear.[3]
  • It is also unresolved whether the apparent postpartum recovery in tear production occurs consistently, because the review explicitly reports disagreement among studies.[3]

Sources

  1. Dry eye, its clinical subtypes and associated factors in healthy pregnancy: A cross-sectional study (PLoS ONE, 2021)
  2. Changes in anterior segment, ocular aberrations, and aqueous humour density during pregnancy and postpartum (European Journal of Ophthalmology, 2026)
  3. Physiological and pathological changes to the eye and vision during and after pregnancy (2024)
  4. Managing of Dry Eye Disease During Pregnancy: Use of Sodium Hyaluronate 0.21 % (Ophthalmology in Russia, 2025)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.clae.2018.10.007, Alternate LINK

Title: The Effect Of Pregnancy On Tear Osmolarity

Subject: Optometry

Journal: Contact Lens and Anterior Eye

Publisher: Elsevier BV

Authors: Mustafa Duran, İnci Güngör

Published: 2019-04-01

Everything You Need To Know

1

What exactly is tear osmolarity, and why is it relevant during pregnancy?

Tear osmolarity is the measure of the concentration of dissolved substances in tears. During pregnancy, fluctuations in hormones, particularly estrogen and androgen levels, can affect the composition of tears, potentially leading to dry eye symptoms. High tear osmolarity indicates a higher concentration of these substances, suggesting insufficient water in the tears, which can irritate the eye's surface.

2

Are hormonal changes during pregnancy the reason for eye changes?

Yes, hormonal changes, specifically those related to estrogen and androgen, are believed to be the primary drivers behind the alterations in tear production and tear osmolarity during pregnancy. These hormonal shifts can influence the function of the tear glands, leading to dry eye symptoms such as irritation and redness. The study mentioned in the text highlights the impact of these hormonal changes throughout the different trimesters.

3

What were the specific findings of the study on tear osmolarity and tear production?

The study followed 30 pregnant women and 30 non-pregnant women for comparison. The pregnant women were assessed in their first and last trimesters. The findings revealed that tear osmolarity decreased slightly as pregnancy advanced. This could be a compensatory mechanism. Additionally, the Schirmer test, which measures tear production, indicated a decrease in tear production in the pregnant group during the last trimester. This highlights how the eyes are affected during pregnancy.

4

What are the common symptoms of dry eye during pregnancy, and how is tear osmolarity related?

Dry eye during pregnancy can manifest as irritation, redness, and a gritty feeling in the eyes. Changes in tear osmolarity can be a key indicator of this condition, as a higher tear osmolarity often suggests a lower water content in the tears. This can then cause inflammation and discomfort on the eye's surface. Therefore, understanding tear osmolarity can help manage symptoms and maintain ocular health during this time.

5

What can someone do to manage dry eye symptoms while pregnant?

If you're experiencing dry eyes during pregnancy, there are several strategies you can try. You can use artificial tears to lubricate your eyes and keep them hydrated. Avoid environments that exacerbate dryness, such as those with low humidity or exposure to wind. If symptoms persist, consult with an eye care professional who can recommend specific treatments tailored to your needs, ensuring optimal eye health throughout your pregnancy.

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