How dehydration impacts your eyes

Medically reviewed by Khuram Sarwar, Dispensing Optician at Feel Good Contacts on 25 May 2023.

• Symptoms of dehydration
• What is dry eye?
• Can my contact lenses become dehydrated?
• Can dehydration cause blurred vision?
• Why is my eyesight getting worse all of a sudden?
• Can dehydration also cause eye floaters?
• How can I hydrate my eyes?

Dehydration can cause numerous effects on your immediate health and wellbeing, whether it’s headaches, sleepiness, cramps, light-headedness or even kidney stones. But what you might not know is that as your body dehydrates, so do your tear ducts – which could result in dehydrated eyeballs or dry eyes, blurry vision and problems to your vision and overall eye health. It is therefore important to drink a good amount of fluid in order to properly hydrate, especially if you do a lot of physical activity. Your body weight is likely to decline when you exercise as your body loses fluid at a rapid rate.

Symptoms of dehydration

Symptoms of dehydration are varied. You might experience a dry mouth, thirst and dry skin and people who are chronically dehydrated may experience a higher blood pressure. Dry eye is another symptom of dehydration and can cause a wealth of issues including eye pain, vision distortion, red eyes and more.

What is dry eye?

Dry eye is when your tear ducts are no longer producing sufficient tears, or some of the tear components may be lacking, causing the tears to break up prematurely and therefore leaving the eyes dry. As a result, eyes aren’t producing the moisture they need to stay hydrated.

Being dehydrated can cause dry eyes and blurry vision as your body will prioritize using water for processes more important such as maintaining the circulation of the brain.

This often causes irritating and uncomfortable symptoms, such as grittiness, redness and blurred vision.

Can my contact lenses become dehydrated?

As your contact lenses rely on the natural moisture of your eyes to remain hydrated and comfortable to wear throughout the day, they’ll start to dry out if your eyes become dehydrated.

It’s also interesting to note that even though high water lenses allow a lot of oxygen through, they could also be unsuitable for dry eyes as they’re thicker. The best lenses for dry eyes are low-mid water lenses.

Can dehydration cause blurred vision?

Dehydration and vision distortion are often closely associated. This is because dehydration causes eye strain which in turn can lead to blurry vision and headaches. Tired eyes are also a symptom of eye strain which can lead to vision distortion. You can get eye strain from spending excessive amounts of time in front of a screen as you tend to blink less during the process. Producing tears by blinking helps to keep your eyes lubricated and hydrated and reduces the probability of experiencing symptoms caused by eyes’ dehydration. For this reason, it may be a good idea to use eye drops such as our Blink Intensive Tears Plus, Hycosan Extra Dry Eye Drops, comfi soothe Drops and Systane Hydration.