Yes, fasting can make dry-eye symptoms worse for some people, especially when fasting also means going without fluids for many hours. However, research on fasting and dry eye is mixed: some studies have found changes in tear-film stability or eye-surface inflammation, while others found no meaningful change in symptoms or tear measurements. The effect may depend on the person, fasting pattern, environment, and existing eye health.
How can fasting affect your eyes?
Your eyes rely on a thin layer of tears called the tear film. This layer keeps the eye surface moist and smooth, supports clear vision, and helps protect the eyes from irritation. Dry eye can develop when the eyes do not produce enough tears, when tears evaporate too quickly, or when the tear film does not work properly. The National Eye Institute explains that problems with tear production or tear quality can lead to dry-eye symptoms.
During a fast that prohibits drinking, going for many hours without fluids may contribute to dehydration. Changes in hydration are one possible factor affecting the eye's surface, but they do not explain every case of dry eye. Fasting may also coincide with changes in sleeping patterns, meal timing, daily activities, or the use of lubricating eye drops. These factors can make it difficult to determine whether fasting itself is responsible for a change in eye comfort.
What does research say about fasting and dry eyes?
Clinical research has produced mixed results. In a 2019 study published in International Ophthalmology, researchers examined 40 healthy people before Ramadan and toward the end of the fasting period. They found that tear-film stability decreased and a test for an eye-surface inflammation marker became positive more often during fasting. However, reported dry-eye symptoms and several other measurements did not change significantly. This suggests that some changes may be detectable on eye tests even when people do not notice a clear increase in discomfort.
A different result was reported in a 2025 study published in Frontiers in Medicine. Among 40 people who completed prolonged religious fasting, researchers found no statistically significant differences in reported dry-eye symptoms, tear-film stability, or tear-meniscus height between fasting and non-fasting periods. Participants used lubricating eye drops less frequently during fasting. Because this was a relatively small study, its findings do not establish that fasting has no effect on everyone.
A 2026 systematic review published in the Journal of Current Ophthalmology assessed 21 studies of fasting and the front structures of the eye. Several studies reported reduced tear-film stability or tear secretion, although findings were not uniform. The review included Ramadan fasting studies, so the results cannot automatically be applied to every form of intermittent fasting, particularly schedules that allow water throughout the fasting period.
Taken together, the evidence suggests that fasting may affect some aspects of the tear film in certain circumstances, but it does not show that fasting consistently worsens dry-eye symptoms or causes persistent dry-eye disease in everyone.
Which fasting-related factors may make dry eyes worse?
If your eyes feel drier on fasting days, the following factors may be relevant:
- Going without fluids: A fast that prohibits drinking may make it harder to maintain normal hydration, particularly during long fasting periods or hot weather.
- Dry or windy surroundings: Air conditioning, fans directed toward the face, wind, and dry air can increase tear evaporation, potentially adding to discomfort.
- Extended screen time: Concentrating on a phone, computer, or tablet can reduce how often you blink, allowing tears to evaporate more readily.
- Changes in eye-drop use: Delaying or skipping lubricating drops because of uncertainty about using them while fasting may affect symptom control.
- Changes in routine: Altered sleep schedules or daily habits may occur alongside fasting and can complicate efforts to identify the cause of eye discomfort.
These are possible contributors, not proof that fasting is the underlying cause. The National Eye Institute identifies dry environments and prolonged screen use as factors associated with dry eye, independently of whether a person is fasting.
What symptoms might become more noticeable during fasting?
Some people may notice changes in eye comfort during the fasting period, especially later in the day. Experiences associated with dry eye can include:
- A gritty or sandy feeling, as though something is in the eye.
- Burning, stinging, or irritation.
- Redness or discomfort around the eyes.
- Blurred vision that may come and go.
- Increased sensitivity to light or difficulty tolerating contact lenses.
- Watery eyes, even when the eyes feel dry or irritated.
These experiences can occur with dry eye, but they can also have other causes. Their timing may provide useful information: symptoms that repeatedly become more noticeable during fasting and improve afterward may suggest a connection worth discussing with an eye-care professional.
How can you reduce dry-eye discomfort while fasting?
Practical steps may help maintain eye comfort during fasting without assuming that dehydration is the only cause.
Maintain hydration during permitted hours
If your fasting schedule permits drinking outside the fasting period, drink fluids regularly during those hours rather than deliberately restricting fluids further. Maintaining normal hydration may be helpful if insufficient fluid intake is contributing to discomfort, although drinking more water is not a guaranteed treatment for dry eye. Anyone who has been given a medical fluid restriction should continue following their clinician's advice.
Use eye drops according to your care plan
Lubricating eye drops, often called artificial tears, can help relieve dry-eye symptoms. Continue any prescribed eye treatment as directed. If you are unsure whether or how to use eye drops during a religious fast, ask your eye-care professional about your medical needs and consult a trusted religious adviser about the rules applicable to your practice. Do not stop necessary treatment simply because you are uncertain about its use during fasting.
Limit avoidable sources of eye irritation
Take regular breaks during prolonged screen use and remember to blink fully. Avoid directing fans or air-conditioning vents at your face, and reduce exposure to smoke, wind, or very dry air when possible. If you wear contact lenses and your eyes become uncomfortable, seek advice about whether you should temporarily switch to glasses.
Keep track of symptom patterns
Notice whether discomfort begins at a particular time of day, occurs only during fasts, or continues after eating and drinking resume. It may also help to note your fluid intake during permitted hours, screen exposure, environment, and use of eye drops. This information can help an eye-care professional assess whether fasting may be contributing or whether another factor needs attention.
When should you seek medical advice?
Arrange an eye examination if dryness continues after fasting ends, keeps returning, becomes progressively worse, or interferes with reading, working, driving, or other daily activities. According to the National Eye Institute, an eye-care professional can assess tear production, how long tears remain on the eye, and the eyelids to help evaluate possible causes. These findings, together with your symptoms and medical history, can guide appropriate care.
Do not assume that significant eye symptoms are simply a result of fasting. The NHS advises urgent medical assessment for eye pain accompanied by severe pain, light sensitivity, changes in vision, or a very red eye. Sudden loss of vision or sudden severe eye pain requires emergency assessment.
If you have an existing eye condition or regularly need lubricating drops, discuss fasting with your treating clinician when symptoms are difficult to control. An individualized plan can help you manage your eye health while taking your fasting schedule and other medical needs into account.