Karwa Chauth 2026: Why fasting may trigger burning eyes and blurred vision

By late afternoon on Karwa Chauth, many women observing the fast may notice a burning sensation in eyes, heaviness in eyes or slightly blurred vision that clears momentarily after blinking. It is easy to attribute these symptoms to hunger or fatigue. However, a full day of fasting, without food or water, can affect the eye surface, with symptoms being more noticeable by evening, just when women head out to prepare for the moon-sighting ritual.

Why your eyes need water

A healthy and adequate tear film is essential for lubricating and protecting the cornea, and ensuring a smooth ocular surface while blinking. The tear film that coats your eyes contains water, mucin and other nutrients, covered by a thin oily layer that helps slow evaporation.

Your body relies on the overall fluid balance to maintain this tear film. Prolonged periods without water may affect tear production, composition and osmolarity and the tears may become more concentrated. These changes can inflame the ocular surface and cause grittiness, stinging or burning sensation. Altered sleep patterns can also contribute to eye fatigue, congestion, discomfort. Some individuals may also experience sensitivity to light, although this can have other underlying causes.

Why vision blurs by evening

A healthy tear film is a smooth, transparent layer, like a clear window. When it becomes thin or irregular, it can scatter light and result in blurred or hazy vision. You may notice that words may appear unclear but become sharper momentarily after blinking. This can be due to a surface problem, rather than a change in your eyesight. Prolonged screen use, reduced blinking, and eye muscle fatigue may further worsen these symptoms. Activities such as cooking, reading, and using mobile phones for extended periods can contribute to eye strain, especially in the presence of dehydration and inadequate rest.

Air pollution

October often brings changing weather conditions, fluctuating humidity levels and increasing concerns about air pollution to the capital. Air pollutants and dust can irritate the eye surface, causing burning, redness, and dryness, while fans and air conditioners further increase tear evaporation. After a day without fluids, the eyes have little defense left, so standing outdoors in poor air while waiting for the moon can aggravate eye irritation, especially in those with pre-existing dry eyes.

Before the fast begins

• Hydrate adequately: Drink water steadily the evening before the fast and at Sargi; include water-rich foods such as cucumber, watermelon, oranges, along with coconut water

• Choose a balanced meal: Include protein, whole grains, nuts and seeds. Omega-3 sources like walnuts and flaxseed can help support overall health

• Limit excess caffeine: Go easy on tea and coffee, especially if it interferes with your sleep

• Prioritise sleep: Ensure sufficient rest and sleep the night before the fast to help minimise fatigue and eye strain

Through the day

• Blink completely and frequently: Make a conscious effort for this.

• Limit screen time: Reduce screen time, take regular breaks. Every 20 minutes, look at something 20 feet away for 20 seconds

• Avoid direct airflow: Direct fans and air-conditioning vents away from your face

• Give rest to your eyes: Resting with closed eyes for a few minutes or short daytime nap can help compensate for disrupted night sleep

• Avoid rubbing your eyes: If your eyes feel irritated, splash cool water on your face with closed eyes rather than rubbing them

• Appropriate eye protection: Wear glasses instead of contact lenses, and sunglasses with full UV protection when outdoors to protect your eyes from direct sunlight and airborne elements

• Minimise exposure to irritants: Avoid areas with dust, smoke, pollution

• Keep lubricating eye drops handy: Preservative-free lubricating drops ease dryness and add to the comfort. If you prefer not use them during the fast, keep them ready for use after moonrise

Breaking the fast

Rehydrate slowly by sipping water slowly rather than drinking large quantities at once, and start with a light, balanced meal, before reaching for sweets. Blood sugar fluctuations can affect vision, particularly in patients with diabetes. Eyes usually feel better with rehydration and rest; however, recovery varies from person to person.

Who needs extra care

Pregnant women, individuals with diabetes, hypertension, kidney disease, or other chronic medical conditions, and those on regular medications should consult their treating physician before attempting dry fasting. Prescribed eye drops should never be discontinued. A modified fast that allows fluids may be a safer alternative.

When to seek help

Seek urgent professional care if you experience sudden vision loss, transient blackouts, a dark curtain or shadow, flashes of light, severe eye pain, marked redness, light sensitivity or fainting. Blurred vision that persists despite rehydration should not be ignored and also needs an examination.

(The author is a consultant ophthalmologist in Delhi)

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.