How Dehydration Affects Your Eye Health
Are you drinking enough water? Dehydration, a condition that occurs when your body loses fluids without replacing them, can cause health issues. Even mild dehydration may affect vision and eye comfort. Fortunately, increasing your fluid intake offers a simple way to improve hydration and protect your eyes.
Why Water Is So Important for the Eyes
Every part of your body needs water, especially your eyes. Water plays an essential role in the health of:
- Tears. The eye's tear film moisturizes the surface of the eye and washes away debris, germs, and allergens. Water accounts for 98% of tear content, according to WebMD.
- The Cornea. The clear, rounded corneal tissue at the front of your eye needs moisture to provide crisp, clear vision.
- The Lens. Dehydration may also affect the lens inside the eye. Together with the cornea, the lens focuses light on the light-sensing retina.
- Blood Flow. Dehydration affects blood flow throughout the body, including the eyes. Blood carries oxygen and nutrients to the eyes and removes waste products.
Vision Problems Caused by Dehydration
Do you know the signs of dehydration? You may be dehydrated if you notice any of these symptoms:
- Thirst
- Dizziness
- Confusion
- Headaches
- Sunken Eyes
- Dry Mouth
- Dark Urine
- Dry Skin
- Fatigue
Try this quick test if you think you might be dehydrated. Pull up on the skin on the back of your hand. If the skin doesn't return to its normal position immediately, you may be dehydrated.
Dehydration can lead to these vision issues:
- Dry Eyes: When your body doesn't make enough tears, your eyes may look red and burn, sting, or itch. It may feel as if there is something stuck in your eyes, and you may notice bright lights irritate your eyes. It's tempting to rub your eyes when they're dry and uncomfortable. Unfortunately, rubbing can create a tiny, painful scratch on your cornea and increase your risk for eye infection.
- Blurry Vision. The tear film helps your eyes stay moist, making it easier for the cornea to focus light rays on the retina. Tear film issues affect the cornea's ability to focus the rays uniformly and may cause blurry vision.
- Eye Strain. Dehydration may also increase your risk for eye strain. Eye strain symptoms include blurry or double vision, and tired, sore, dry, or watery eyes. If you have eye strain, the muscles in your neck, shoulders, and upper back may feel tight.
- Eye Diseases. Chronic dehydration could raise your risk for certain eye diseases. Cataracts and retinal vascular disease may be associated with dehydration, according to Clinical & Experimental Ophthalmology. Cataracts cloud the eye's lens, while retinal vascular disease affects the blood vessels in the retina.
- Contact Lens Issues. A healthy tear film is essential for contact lens comfort. Your contact lenses may become uncomfortably dry if you're dehydrated.
What You Can Do to Prevent Dehydration
Preventing dehydration can be as simple as following these tips:
- Increase Fluid Intake. Boosting your fluid intake will help you avoid dehydration. Water isn't the only source of hydration for your body. Other beverages and the foods you eat also contain water. WebMD suggests drinking a minimum of six to eight cups of water or fluid every day.
- Drink More on Hot Days or When You're Sick. You lose fluids when you sweat, vomit, or have diarrhea. Drinking more water in these situations can help you prevent dehydration.
- Limit Caffeine and Alcohol. Caffeine and alcohol are naturally dehydrating. Avoiding these substances or drinking beverages containing caffeine or alcohol less often can help you avoid dehydration.
- Talk to Your Optometrist About Your Dry Eyes. If your dry eye symptoms continue despite increasing your water intake, give your eye doctor a call. Your optometrist can recommend helpful dry eye treatments that will improve eye moisture.
Do you have a concern about your eye health or need new eyeglasses or contact lenses? Contact our office to make an appointment with the optometrist.
Sources:
WebMD: Why Are Tears Salty?, 2/15/2026
https://www.webmd.com/a-to-z-guides/why-are-tears-salty
All About Vision: How Dehydration Can Impact Eye Health and Vision, 10/15/2025
https://www.allaboutvision.com/conditions/related/does-dehydration-affect-eyes/
PubMed: Clinical & Experimental Ophthalmology: Hydration, Fluid Regulation and The Eye: In Health and Disease, 11/2015
https://pubmed.ncbi.nlm.nih.gov/25950246/
MedlinePlus: Dehydration, 12/29/2023
https://medlineplus.gov/dehydration.html
WebMD: Dehydration Treatment: How to Rehydrate Fast, 7/27/2025
https://www.webmd.com/a-to-z-guides/dehydration-in-adults-treatment
NCBI: StatPearls: Adult Dehydration, 3/5/2025