Dehydration and Eye Health: How Staying Hydrated Protects Your Vision

When you consider that our bodies are around 60% water, it’s no wonder that hydration is so important. However, the eyes have a particular interest in your attention to hydration because they are 98% water. That means every time you’re dehydrated, your eyes suffer the consequences, some of which affect vision health.

This is why optometrists consider hydration an essential step in lifetime eye health.

Hydration & Vision: Why Our Eyes Need 12 to 15 Cups Per Day 

Every time you blink, they are washed and lubricated via a substance called lacrimal fluid (tears). And the center of your eye is filled with a gel-like substance, called the vitreous humor, which is 99% water. When you’re dehydrated, it reduces the amount of water available to the eyes, and this can have serious consequences.

To support whole-body and vision health, most physicians recommend drinking between 11 and 15 cups of water per day, depending on the season, your exercise, and other lifestyle habits. 

Symptoms of dehydration include:

• Feeling thirsty (by the time you feel thirsty, your body is starting to dehydrate).
• Dry mouth, lips, or tongue.
• Dry skin.
• Dry eyes.
• Fatigue or lethargy.
• Headaches.
• Darker urine (urine should be a very pale yellow).
• Muscle cramping.

Over time, chronic hydration can lead to more serious side effects or complications, some of which affect your eye health and vision.

Common eye conditions affected by dehydration

As we enter fall and winter, which tend to have lower humidity levels both outdoors and inside, it’s even more important to make sure you’re getting the fluids your eyes need. Here are some of the most common eye conditions that can be caused or worsened by not staying hydrated.

General eye irritation

The eyes rely on regular blinking and adequate lacrimal fluid (tears) to stay moist and lubricated. When you’re dehydrated, the body can’t produce adequate tears to keep your eyes moist. When the eyes are dry, they can become red, irritated, itchy, and inflamed. They may also feel gritty and can be more sensitive to light. And, of course, if your eyes are irritated, they’re far more prone to eye strain. 

Eye infections

We mentioned above that hydration is essential to whole-body health, with the eyes among the first anatomical structures to show signs when they don’t get enough water. As a result, hydration is also essential for healthy immune system function.

When you’re not staying hydrated, it can weaken the immune system, elevating your risk of infections. And, because the eyes are 99% water, they are more susceptible to infections when there aren't enough tears to provide adequate protection from bacteria, viruses, or fungi. This makes you more prone to developing eye infections.

Dry eye

Dry eye is a condition that settles in as a result of chronically dehydrated eyes. Certain factors, such as aging, menopause, illnesses, or medications, can increase your risk of developing dry eye. Excessive computer and screen use is also a contributing factor, as we blink less often when staring at screens.

However, inadequate hydration is also a significant cause of dry eye. Characterized by red, irritated, and dry eyes (which result in excess rubbing). These symptoms also cause blurred vision. Interestingly, excessive tearing is also a sign of dry eye. However, this tearing is a desperate attempt by your eyes to ease dry eye irritation. If you’re dehydrated, excessive tearing only makes you more dehydrated, worsening the problem.

If you experience dry eye symptoms, make sure you’re hydrating sufficiently. You can give your eyes an extra boost by keeping preservative-free eye drops handy in your car, purse, briefcase, end table, and whenever you’re working or using screens. 

NOTE: Using the 20-20-20 rule to prevent eye strain, especially when you’re using screens, can also help to prevent dry eye symptoms.

Retinal tears or detachment

The retina is located at the rear of the interior eye cavity. It is responsible for processing visual information via a specialized set of photoreceptor cells called rods and cones. These photoreceptor cells convert the light that enters through the pupil into electrical signals, which are then transmitted via the optic nerve to the brain. When the fragile, sensitive tissue is torn or pulled away from the retina, vision is threatened. If a retinal tear or detachment isn’t treated in time, it can lead to severe visual impairment or legal blindness. And, sometimes, these tears or detached retinas defy treatment, which has permanent effects.

These injuries can occur as a result of severe eye trauma, like being hit in the eye or a traumatic accident. However, most of the time, they occur because the vitreous humor, the gel-like substance in the middle of the eye (99% water), begins to harden and pull away from the retina. Because it is sticky, it can begin pulling the retinal layer with it, leading to tears or detachment. Whole-body hydration is essential for providing the liquid necessary to keep the vitreous humor healthy and less sticky.

Other eye issues related to dehydration

Because hydration is so vital to eye health, dehydration has also been linked to other eye issues that cause vision loss, including:

• Cataracts. Dehydration can lead to lens thickening, increasing the risk of cataracts.
• Glaucoma. Studies consistently demonstrate that drinking sufficient water helps maintain healthy intraocular pressure (the pressure inside the eye). Interestingly, dehydration is linked to increased pressure inside the eye, which can lead to glaucoma.
• Retinal vascular disorders. Lack of fluids in the body creates sluggish circulation. This can affect the vascular network that serves the retina, contributing to retinal vascular disease.

Eye to Eye Family Vision Care Reminds Patients to Give Their Eyes a Drink

Here at Eye to Eye Family Vision Care, we like to remind patients that hydration is a pillar of a healthy diet, which is a foundation for eye health. Do your eyes a favor: give them a drink. Make sure you drink at least 8 to 10 cups of water per day (more during dry seasons, if you spend time in conditioned air, or if you live an active lifestyle). 

Are you experiencing dry eyes or chronic eye irritation? Has your vision changed since your last eye exam? Schedule an appointment with Eye to Eye, and we’ll get you back on track.