Article first published: January 2022
What does your eye health have to do with your favorite place? Take a minute to think back to the last time you visited your feel-good place. What thoughts are running through your mind? They are probably visual impressions, including colors, the mood of the light and the scene where a special event took place. It’s no wonder, because the eyes are a human’s most important sensory organ – they shape our perception. Oftentimes, we don’t notice how important it is to have healthy eyes until our vision deteriorates, reading becomes more difficult or we have problems with near or far vision.
There are factors that make a much more subtle impact on our eyes and have effects we don’t notice directly. These challenges include UV radiation and so-called blue light.
UV radiation places our eye health at risk in a number of ways: Acute eye damage occur if you spend hours in the sun without protection – including reddening, rashes, allergies or sunburnt eyelids, or even acute photokeratitis (also known as “UV keratitis”), a type of sunburn of the cornea. Excessive sunlight can also cause conjunctivitis. Over the long term, frequent, unprotected exposure to UV light speeds up the formation of cataracts. UV is also suspected of causing cancer of the eyelid.
ZEISS expert Dr. Christian Lappe: Does sunlight harm my eyes?
Another often underestimated factor is that our eyes need full UV protection throughout the day – and not just in bright sunlight. This is because we are all exposed to significantly more UV radiation due to scatter radiation throughout the year than we are by direct sunlight. Certain cloud formations can actually increase the level of UV exposure compared to a clear day. Scientists in Kiel, Germany, already proved some time ago that fleecy clouds (Cumulus humilis) in particular actually intensify UV radiation.1 The risks posed by UV light are therefore not due to direct sunlight but rather diffuse sunlight which is also known as scatter radiation.
Many people are aware that UV radiation from the sun is harmful for our eyes. Nonetheless, the results of a survey conducted by ZEISS in 2018 showed that 80 percent of respondents didn’t realize that clear eyeglass lenses can also provide protection against harmful radiation from the sun. When it comes to UV protection, most people think of sunglasses first and foremost.
But these days, anyone can get full UV protection in their everyday glasses with clear lenses. The key to this is special additives in the lens material that almost completely block damaging UV radiation. Admittedly, this isn’t a completely simple process, because many synthetic materials are discolored by these types of absorbent substances if even minimal deviations occur in the manufacturing process. But with ZEISS UVProtect technology, lenses provide full UV safety and transparency.
It goes without saying that sunglasses also play their part in providing our eyes with the best possible protection against the harmful effects of sunlight. But not all sunglasses are equal, because everyone has different preferences and expectations when it comes to tinting, mirror coatings and whether or not the glasses should have polarized lens.
ZEISS is continuously researching this area with the goal of offering everyone who wears sunglasses a custom solution – for instance, self-tinting eyeglass lenses like ZEISS AdaptiveSun. Because one thing’s for certain: People will only like wearing sunglasses and wear them often if they find them comfortable and suitable as well as stylish and on trend.
It’s important to mention the topic of glare protection, too. Because when sunglasses provide glare protection, it’s automatically assumed they provide effective UV protection as well. But that’s not the case. Just because a pair of sunglasses has dark lenses, tinting or glare protection doesn’t mean it offers excellent protection against UV radiation. If your sunglasses or eyeglasses with tinted lenses feature a low-quality UV filter, wearing them can actually do more harm than if you’re not wearing any glasses at all.
That’s because dark lenses let less light through, causing the pupil to dilate. So if you’re wearing tinted glasses with a poor-quality UV filter, more harmful radiation can make its way through to the retina. That’s why a good UV blocker is the most important feature of any sunglasses besides glare protection. And this is also why all ZEISS eyeglass lenses automatically come with comprehensive UV protection up to 400 nm – clear eyeglass lenses and sunglass lenses alike.
The day-to-day strain placed on our eyes has changed an enormous amount. We now spend several hours every day looking at smartphones or tablets. We direct our gaze downwards much more often when using a smartphone. Oftentimes, we don’t even set them down when we’re walking, shopping or playing sports. Our eyes have to do a great deal of work to continually accommodate for this, constantly adjusting to various distances – near, mid-range and far.
On the whole, it can be said that we’re spending far more time looking at things “up close” than we did before. We don’t look into the distance often enough especially when working from home, as many of us are right now, so our eyes don’t have as much opportunity to relax. This is why people report feeling that they can’t see as well after spending a long day on the computer.
Experts call this visual fatigue "digital eye strain". Symptoms include
- Eye pain
- Stinging eyes
- Dry or even watery eyes
- Light sensitivity
- Neck, back and shoulder aches due to posture
- Blurry vision
- Double vision
- Eye twitching
- Red and itchy eyes
In our increasingly mobile world, there are now eyeglass lenses support comfortable vision. SmartLife lenses from ZEISS for normal, everyday glasses were specially developed to support the eyes when constantly switching between near and far, for example – with large fields of vision for all distances and directions.
ZEISS SmartLife is an exciting option for people between 30 and 45 years of age in particular. Our eyes are still in good shape at this point, and presbyopia, a loss in the ability to focus on close objects that occurs with age, is still (far) in the future. But even at this point, our eyes have a lot to cope with due to everyday requirements and need relief. This is where the digital version of ZEISS SmartLife comes in, offering specific support for up-close tasks.
Another factor is that digital displays emit blue light which plays a significant role for our eyes in terms of well-being. Blue light has a tendency to scatter more due to its short wavelength. Some people describe this as a distracting glare and impaired contrast sensitivity. Blue light can have a concrete influence on our visual comfort as a result.
The human body does, however, need a certain amount of blue light to control the sleep and wake cycle. Blue light has an activating effect – but this is what makes it less advantageous in the evening hours. At this time of day, it’s better to put our smartphone or laptop aside and relax.
ZEISS expert Dr. Christian Lappe: Does blue light reduce visual comfort?
ZEISS expert Dr. Christian Lappe: Does blue light have an influence on our wellbeing?
Another question that always comes up when discussing this topic is whether blue light can damage the eyes. For now, experts say that radiation from digital devices, displays, monitors and normal indoor lighting doesn’t pose a risk. As things currently stand, studies with patients have not yielded any concrete evidence that these devices present a health risk for the retina. Nevertheless, patient complaints of decreased visual comfort, asthenopic symptoms such as blurred vision, burning, painful or tired eyes, and eyestrain are common and familiar topics to eye care professionals.
The latest organic and chemical technology now enables the lenses to filter out a significant proportion of the blue light that puts strain on the eyes. These blue light reducing properties are a component in the material of the ZEISS BlueGuard lenses, which block up to 40 percent of the potentially harmful and irritating blue light in the wavelength between 400 and 455 nanometer (nm), which is known to be linked to digital eye strain.2 The positive properties of blue light, on the other hand, which lie in a higher wavelength range from about 455 to 500 nm, remain specifically unaffected with ZEISS BlueGuard lenses. This makes it possible to prevent digital eye strain to some extent. These lenses also include the crucial UV protection of up to 400 nm mentioned above which is provided by the ZEISS UVProtect technology.
On the whole, it can be said that there are many things we can do to help our eyes and boost our everyday well-being in terms of our sight. Eyeglass lenses can play a role in this – they are much more than just corrective lenses.
1 https://oscb-berlin.org/deu-facts-index#Office-Eye-is-caused-by-Rare-Blinking-and-Desiccating-Environment1: N.H. Schade, A. Macke H. Sandmann, C. Stick: Hochaufgelöste Strahlungs- und Bedeckungsgradmessungen während der Sommermonate 2004/2005 in Westerland (Sylt) [High-resolution radiation and cloud coverage measurements during the summer months of 2004/2005 in Westerland (Sylt)].https://meetings.copernicus.org/dach2007/download/DACH2007_A_00167.pdf
2 Own measurements and calculations based on the BVB (blue violet block) metric. Evaluations of Technology and Innovation, ZEISS Vision Care, DE 2020