person's right eye

If there is one guarantee in life, it’s that drinking enough water provides health benefits. While it’s true that there are risks associated with drinking too much water too, keeping the body’s water levels at the optimal level has a greatly positive impact on overall wellness and health. 

What causes dehydration?

For those of you who don’t know, dehydration is a symptom of not drinking enough water. 

If you do a lot of physical activity, you will be more prone to dehydration as our bodies lose fluid at a rapid rate through sweat. It is, therefore, important to replenish the water that we use every day to ensure that our vital bodily functions work properly.

How can you tell if you are dehydrated?

The symptoms of early dehydration are relatively intuitive. Very often, you might recognize them as common sensations like dry mouth and feeling thirsty, but severe dehydration can also present as dry skin. 

Dehydration can have an immediate impact on health and well-being, whether it’s headaches, sleepiness, cramps, or light-headedness. Over extended periods it can lead to long-term problems such as kidney stones and high blood pressure.

Similarly, eyes are a tell-tale signal of many health issues, including dehydration. If you experience dehydrated eyes, you might experience eye pain, vision distortion, red eyes, or discomfort. Chronic dehydration can contribute to the development of long-term eye problems like floaters or a condition known as ‘dry eye.’ 

What is dry eye?

A dry eye is when your tear glands fail to produce tears in the right volumes or of adequate quality to lubricate your eyes sufficiently. This can look like watery eyes, wherein the fluid produced by the eye is missing key components needed to nourish the eye, so it overcompensates, or it can be a lack of fluid altogether. As a result, eyes are starved of the moisture they need to keep them hydrated.

This condition happens when you are experiencing dehydration because the body will prioritize its limited fluids for more important processes, such as maintaining circulation in the brain. When dry eyes persevere for too long, it can cause further breakdown within the eye and lead to floaters.

What are floaters in the eye?

Eye floaters appear as moving spots in your vision. They occur when the vitreous humor, a gel-like substance that makes up the main body of the eyeball, loses its shape. 

Although this condition is relatively common and mostly associated with natural aging or age-related changes to the eye, dehydration can be a causal factor too. That’s because the vitreous humor has a composition of collagens, proteins, and 98% water. When dehydration occurs, the vitreous humor dries out and allows some proteins to solidify instead of remaining dissolved. This makes them detectable by the retina as they float around the inside of the eyeball. 

Can dehydration cause blurred vision?

Blurred vision or vision distortion are very common conditions, but the cause can vary. Dehydration can be a causal factor as it can result in eye strain, which is often associated with blurry vision, headaches, and tired eyes. 

Excessive screen usage is frequently attributed as the cause of eye strain owing to a phenomenon that slows down blink rate (how frequently we blink) when using screens. As blinking introduces moisture to the eye and replenishes the tear film, infrequent blinks can lead to drier eyes.

Can my contact lenses become dehydrated?

Contact lenses are made from soft or semi-soft plastic materials that are often porous so that they can absorb moisture. However, contact lenses cannot produce moisture by themselves. So that they can sit comfortably in our eyes, they need to be surrounded by enough fluid in the eye to rest on the tear film. 

If your eyes are dry, your contact lenses will be too. When contact lenses are too dry, they dehydrate and can shrink a little. This will affect the fitting, make the contact lens feel uncomfortable in the eye, and it will also become much more difficult to remove at the end of the day.

Higher water-content lenses draw moisture away from the eye more easily than lower water-content alternatives. That means that higher water-content lenses are not necessarily more suitable for those who suffer from dry eyes. Lens technology has been developed to address this issue, with soft contacts now on the market that range between 38% and 79% water content. Your optician will bear these factors in mind to help them determine the most suitable lens for each patient.

Easy ways to keep eyes hydrated

If you feel that you might be at risk of developing dehydration, there are a few lifestyle changes that can help to set you on the right course.

Drink plenty of water

Keeping fluid levels up flushes out toxins. This helps to maintain healthy eyes and prevent developing conditions such as dry eye, irritation, or floaters.

Take regular screen breaks

Activities like using a computer, or smartphone or watching TV for prolonged periods reduce your blink rate. As a result, your eyes do not get a chance to recover, which may result in dry eyes. A memorable 20-20-20 rule can help reduce the impact of digital screens on eyesight. Every 20 minutes, simply look 20 feet into the distance for 20 seconds. Regular blinking exercises play an important role too.

Avoid using air conditioning, fans, or indoor heating for extended periods of time

The air around you can become too dry. This can have a drying effect on your eyes, and this is especially the case for contact lenses. An alternative way to protect your eyes from this is to introduce a humidifier to your home or workplace to counter the effects of these influences.

Use the correct eye drops 

Specially formulated eye drops or gels offer a preventative measure or will provide fast relief for dry eyes. If you wear contact lenses, make sure the drops you use are suitable to use with your contact lenses. 


About Tina Patel

Tina Patel is a qualified Contact Lens Optician at Feel Good Contacts. She achieved a BSc (Hons) in Optical Management in 2002 from Anglia Ruskin University, Cambridge, and qualified as a Dispensing Optician. In 2007, Tina went on to qualify as a Contact Lens Optician. With over 25 years of experience in the optical industry, she has worked for a leading high street optician and also spent 6 years teaching at City, University of London.