How does dehydration affect your eyes?

Dehydration can have a number of unwanted effects on your body, and your eyes are no exception.

Eye health

Sonia Chartier

17 June 2019


As we all know, water is essential to life. Your body requires water for a wide range of processes: water surrounds and lubricates the joints, flushes out toxins and waste through urine, helps regulate blood pressure and more. So if you don't make sure to drink plenty of water regularly, many of your bodily processes can suffer.

You're technically dehydrated if your body is losing more water than it is taking in. For example, your body loses water through urine and sweat. Plus, dehydration can result from a bout of sickness or diarrhea, so it's important to replenish vital fluids as much as you can during and after this time.

How does dehydration affect your eyes?

To function properly, your eyes need water just as much as your joints or kidneys. A layer of tears should always cover your eyes in order to lubricate and protect them by washing away debris and bacteria. Every time you blink, tears are spread over the surface of your eyeball, even though you probably won't notice them until you laugh or cry and the tears spill out of your eyes.
Without sufficient levels of water, however, your body is unable to create the tears to lubricate and protect your eyes. This means that you can suffer from a range of uncomfortable symptoms.

Dry eyes

Dry Eye Syndrome occurs when the body is unable to produce enough tears to lubricate and moisten the surface of the eyeball. If you're dehydrated, your body will conserve water for vital processes like maintaining blood flow to the brain, and organs such as your eyes can be the first to suffer. Common symptoms of dry eye include:

  • Swollen, red or painful eyes
  • Irritated or itchy eyes
  • Discomfort when wearing contact lenses
  • A sandy or gritty feeling in the eyes
  • Waking up with eyes stuck together with mucus


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A.Vogel's Eye Drops can be used to soothe and moisten dry eyes, even while wearing contact lenses. Apply 1 drop in each eye 4 to 5 times daily, or more often as required.


Eye strain

If you're dehydrated, you're also more likely to suffer from eye strain. This means that your eyes could be at greater risk of becoming tired and irritated, and you could be more likely to suffer from symptoms such as headaches and itchy or dry eyes.

You're especially at risk of eye strain if you spend all day using a computer for work. Ever heard of Computer Vision Syndrome? It's a condition that can arise from spending a great deal of time looking at screens—your PC at work or the TV at home—without taking a break to rest your eyes. Staying hydrated will help keep your brain running smoothly and help avoid headaches and eye strain. But you should also make an effort to take regular breaks from your screens to give your eyes a much-needed rest.

Puffy eyes

When fluid levels become low, your body's survival instinct kicks in and it begins to stockpile as much water as possible. If you aren't drinking enough water, this could trigger fluid retention, which can make your eyes puffy and swollen.
What's more, excess salt can also trigger this sort of fluid retention. While you might think that you're drinking plenty of water, consuming too much salt can also affect your water levels and cause your body and eyes to become dehydrated and swollen.
Puffy eyes can be both uncomfortable and unsightly, and tend to be at their worst in the morning if the cause is fluid retention. You can read more about puffy eyes in the morning here. Make sure to drink plenty of water to flush out excess fluid, and gently massage the area to reduce swelling.

How to keep your eyes happy

  • Drink water! To keep your eyes hydrated and working nicely, you need to drink at least 1.5 to 2 litres of fresh, plain water every day (even more in hotter climates or if you've been exercising and sweating a lot). Carrying a refillable water bottle with you at all times can be a good way to remind yourself to keep drinking plenty of fluids.
  • Try Sharp Vision to keep your eyes in good working order. Sharp Vision contains zinc as well as naturally occurring lutein, beta-carotene and zeaxanthin, all of which are great for healthy eyes and vision.
  • Eat a rainbow of fruits and veggies! Red bell peppers and tomatoes; purple carrots and blackcurrants; leafy greens like spinach and kale; sweet potatoes and orange carrots. These brightly coloured fruits and vegetables are packed with eye-friendly vitamins and nutrients, so make sure to eat a wide range of them to keep your eyes in tip-top shape.
  • Never go to sleep wearing contact lenses or makeup. Contact lenses can become a breeding ground for bacteria when your eyes close and the supply of oxygen is reduced. Similarly, sleeping with eye makeup on can disrupt the natural cleaning process your eyes go through during the night and can encourage bacteria to build up in and around your eyes.
  • Always wash your hands before touching your eyes. Touching your eyes with unwashed hands can spread bacteria and put you at risk of developing eye infections and styes. Plus, rubbing your eyes when itchy or irritated can put you at risk of scratching them or bursting the tiny, delicate blood vessels you can see on the surface of your eyes. Itchy eyes can be calmed with a cold, clean compress.

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