When the temperature rises, we're reminded to drink more water to stay healthy and energised. Most people understand that hydration affects energy levels, skin health and concentration, but far fewer realise how significantly it impacts their eyes.
Your eyes are often one of the first places dehydration shows up and, during the warmer summer months, keeping them well hydrated is more important than ever.
Here's why hydration matters for your vision, the warning signs of dehydrated eyes, and how to keep them comfortable all summer long.
Why Your Eyes Need Water
Your eyes depend on a healthy tear film to function properly. This thin layer of fluid covering the surface of the eye does far more than simply keep your eyes moist. It helps protect against infection, washes away debris, delivers oxygen and nutrients to the cornea, and maintains clear, stable vision.
Tears are approximately 98% water. When you're dehydrated, your body prioritises vital organs and reduces the fluid available for tear production. The result is a compromised tear film that breaks down more quickly, leaving your eyes exposed, uncomfortable and struggling to see clearly.
Signs Your Eyes Are Dehydrated
Dehydrated eyes don't just feel dry. Symptoms can be surprisingly varied and may include:
- Dryness, grittiness or a burning sensation
- Redness and irritation
- Blurred vision that fluctuates when you blink
- Increased sensitivity to light
- Eye fatigue, particularly after screen use
- Excessive watering as the eye attempts to compensate for dryness with reflex tearing
If you notice these symptoms worsening during hot weather, dehydration may be a contributing factor, even if you don't feel noticeably thirsty. By the time thirst develops, you may already be mildly dehydrated.
Dry Eye: A Modern Epidemic
Whilst dehydration can contribute to eye discomfort, it is important to recognise that dry eye disease is often much more complex.
Dry eye disease is one of the most common reasons patients seek advice from eye care professionals today and is increasingly being described as a modern epidemic.
Dr Stephen Hannan, Group Clinical Services Director at Optical Express, explains:
"Dry eye disease has become a modern-day epidemic. We are seeing increasing numbers of patients affected by symptoms such as irritation, fluctuating vision, tired eyes and excessive watering. While hydration is important, dry eye is rarely caused by a single factor. Environmental conditions, increased screen use, ageing, contact lens wear, underlying health conditions and even medications prescribed for general health can all contribute to the development of dry eye disease. In my experience, dry eye complaints are more frequently associated with environmental or habitual factors, such as the use of mobile devices, than as a side effect of eye surgery."
Modern lifestyles place significant demands on the ocular surface. Increased use of smartphones, tablets, computers and other digital devices reduces blink frequency, allowing tears to evaporate more quickly. Many people now spend several hours each day looking at screens, often in air-conditioned environments that further accelerate tear evaporation.
In addition, a wide range of commonly prescribed medications can contribute to dry eye symptoms. These include antihistamines, antidepressants, blood pressure medications, hormone therapies and medications used to manage chronic health conditions. For many patients, dry eye develops gradually and may worsen over time without them recognising the underlying cause.
Air conditioning, central heating, low humidity, pollution, wind exposure and seasonal allergens can all disrupt the natural tear film and contribute to symptoms. As a result, effective dry eye management often requires more than simply drinking more water. Identifying and addressing the underlying causes is key to achieving long-term improvement.
Summer Makes It Worse
Several summer-specific factors can increase both dehydration risk and eye discomfort.
Heat and Perspiration
Hot weather increases sweating, accelerating fluid loss throughout the body. Unless you actively increase your water intake to compensate, dehydration can occur more quickly than expected, particularly during outdoor activities or exercise.
Air Conditioning
Spending time in air-conditioned offices, cars and shops reduces humidity in the surrounding air. Low humidity accelerates tear evaporation, making dry eye symptoms significantly worse.
Increased Outdoor Time
Longer days often mean more time spent outdoors in the sun, wind and pollen. These factors can irritate the eyes and accelerate tear evaporation. Combined with dehydration, outdoor activities can leave your eyes feeling particularly uncomfortable by the end of the day.
Hydration and Contact Lens Wearers
If you wear contact lenses, staying hydrated during summer is especially important.
Dehydrated eyes can struggle to maintain the moisture levels needed for comfortable lens wear. Contact lenses themselves can also influence the ocular surface environment. Soft contact lenses absorb and retain water, and prolonged lens wear can contribute to instability of the tear film in susceptible individuals. For some patients, this can lead to symptoms of dryness, irritation, fluctuating vision and reduced comfort, particularly during hot weather, prolonged screen use or when spending time in air-conditioned environments.
For patients who experience persistent contact lens-related dryness, it may be worth discussing alternative forms of vision correction with an eye care professional. Surgical vision correction can remove the ongoing need for contact lenses, eliminating one factor that may contribute to ocular surface discomfort. Whilst surgery is not a treatment for dry eye disease itself, many patients find that removing the requirement for daily contact lens wear helps improve comfort and simplifies long-term management of their ocular surface health.
Modern vision correction options include laser eye surgery, lens replacement surgery and cataract surgery, allowing many patients to achieve greater freedom from glasses and contact lenses whilst maintaining excellent visual outcomes.
How to Keep Your Eyes Hydrated This Summer
Drink More Than You Think You Need
The NHS recommends six to eight glasses of fluid each day, but requirements often increase during hot weather and physical activity. Don't wait until you feel thirsty. Instead, keep a water bottle with you throughout the day and sip regularly. Water, herbal teas and water-rich foods such as cucumber, watermelon and strawberries all contribute to hydration.
Use Preservative-Free Eye Drops
Preservative-free lubricating eye drops can supplement your natural tear film and provide quick relief from dryness and irritation. They're particularly useful when spending time in air-conditioned environments, during long journeys or when using digital devices for extended periods.
Limit Alcohol and Excess Caffeine
Alcohol can contribute to dehydration and may worsen dry eye symptoms. Whilst moderate caffeine intake is generally well tolerated, it is sensible to balance caffeinated and alcoholic drinks with adequate water intake, particularly during hot weather.
Take Regular Screen Breaks
Screen use significantly reduces blink frequency, accelerating tear evaporation. The 20-20-20 rule remains one of the simplest and most effective ways to reduce digital eye strain: every 20 minutes, look at something approximately 20 feet away for at least 20 seconds. Remember to blink consciously and fully when using smartphones, tablets and computers.
Wear Quality Sunglasses
Wraparound sunglasses provide protection from UV radiation, wind and airborne irritants, all of which can contribute to tear film instability. They are not simply a fashion accessory; they also help preserve the tear film and improve comfort outdoors.
When Dry Eyes Persist
If dry, uncomfortable eyes persist despite staying well hydrated, it may indicate an underlying dry eye condition rather than simple dehydration.
Dry eye disease affects millions of people across the UK and Ireland and is becoming increasingly common. The condition is often multifactorial, with contributing factors including age, hormonal changes, screen use, environmental conditions, contact lens wear, certain medications and underlying health conditions.
Modern diagnostic technology allows eye care professionals to assess the quality and stability of the tear film, evaluate the health of the eyelids and meibomian glands, and identify the root causes of symptoms.
Treatment options may include:
- Preservative-free lubricating eye drops
- Prescription therapies where clinically appropriate
- Management of meibomian gland dysfunction, for example LipiFlow, which is available at Optical Express
- Intense Pulsed Light (IPL) therapy
- Lid hygiene and warm compress programmes
- Nutritional and lifestyle advice
- Advanced ocular surface treatments, including amniotic membrane therapy in selected cases
The earlier dry eye disease is identified and treated, the greater the opportunity to improve comfort, vision quality and long-term ocular surface health.
Looking Beyond Hydration
At Optical Express, our clinicians regularly assess and manage patients with dry eye disease using advanced diagnostic technology and evidence-based treatment pathways. Whether symptoms are related to dehydration, screen use, environmental factors, contact lens wear or an underlying ocular surface condition, identifying the root cause is essential to achieving long-term improvement.
For suitable patients, vision correction surgery may also form part of the long-term solution by removing the need for contact lenses and reducing one of the factors that can contribute to ocular surface discomfort.
As Dr Stephen Hannan explains:
"Whilst hydration and lifestyle modifications remain important, dry eye disease often requires a personalised approach. Understanding the underlying causes allows us to recommend the most appropriate treatment strategy, whether that involves ocular surface therapies, changes to contact lens wear, or, for suitable patients, exploring vision correction surgery as a way of reducing long-term dependence on contact lenses."
Small Steps, Big Difference
Keeping your eyes hydrated during summer doesn't require significant effort, just consistent habits. Drink water regularly, use eye drops when needed, protect your eyes outdoors and take regular screen breaks throughout the day.
Your eyes will feel more comfortable, your vision will be clearer and you'll be able to enjoy everything the summer has to offer without the distraction of dry, irritated eyes.
If you are experiencing ongoing symptoms of dry eye disease, a comprehensive assessment can help identify the underlying causes and ensure the most appropriate treatment plan is put in place, helping you enjoy healthier, more comfortable vision throughout the summer and beyond.
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