Introduction. The Digital Generation

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2 Introduction We live in a digital era and with new digital devices hitting the shelves every day is a fact that we spent most of our time looking at electronic devices. However, our visual processing system was not designed for these long and stressful hours of screen time. Unlike our ancestors in the stone age, nowadays our vision works at a maximum 24/7 and chances are that very few of us is taking any protective measure to protect our eyes from all the stressful lights that comes our way. It is no coincidence then that many people report UNPLEASANT PHYSICAL SYMPTOMS like visual fatigue, blurry vision, red, dry and itchy eyes, headaches, migraines and other problems after prolonged exposure to digital devices, artificial lighting and other stressful visual stimuli. But it doesn t have to be this way. There are things that you can do to prevent this epidemic of tired eyes. DIM RED LIGHTING at home and SPECIALIZED EYEWEAR for the digital user are probably the single two best things you can do for your eyes. Specialized eyewear consists of PRECISION TINTED LENSES that work by selectively regulating the transmission of high intensity lights such as the ones that are built-in in most digital displays or the annoying flickering lights present in artificially lighted environments. By filtering and blocking the specific wavelengths of light that are known to cause problems these lenses can eliminate and reduce all the annoying symptoms people get after prolonged hours in front of the screen. The Digital Generation On average, more than NINE IN TEN ADULTS (93,3%) spend MORE THAN TWO HOURS each day using a digital device and more than SIX IN TEN ADULTS (60,8%) spend FIVE OR MORE HOURS on a digital device each day. Children are extremely exposed to the epidemic of digital eye strain and parents should take this matter very seriously. Nearly ONE IN FOUR KIDS spends more than THREE HOURS A DAY in front of a screen. Easier said than done since computers and smartphones have become a part of their life. From school assignments to socializing with other children through social media, this constant use of technology leaves them prone to visual fatigue and can compromise their normal visual development. That s why parents should monitor, not only the amount of time their kid s spend behind a screen, but also any physical symptoms they might be experiencing. Blurry eyes and headaches are definitely red flags.

3 Now let s dig a little bit more about how the chronic use of technology is affecting your vision and your health and what you can do about it.

4 Digital Eye Strain has become epidemic According to The Vision Council, Digital Eye Strain can be defined as the physical discomfort resulting from exposure to a digital screen, whether you are using a computer, laptop, smartphone, tablet, e-reader or any other digital device. Office workers and people with computer oriented jobs are the most affected, since they are the ones exposed to long hours of screen time and artificial lighted environments. The most common symptoms of DIGITAL EYE STRAIN are visual fatigue, dry, itchy or burning eyes, blurry vision, headaches, migraines, and dizziness, among others things. These symptoms can be painful and, in extreme cases, debilitating. That s why is so important to protect your eyes with the correct type of PROTECTIVE EYEWEAR. The following are the most COMMON COMPLAINTS and the clearest warning signals that you might be suffering from digital eyestrain or that you have developed some degree of LIGHT SENSITIVITY:

5 Photophobia and Light Sensitivity Photophobia is just another name for light sensitivity, which basically means intolerance to light (especially bright light). And some people become intolerant to light because light causes them painful reactions. The most common problematic light sources among affected individuals are bright lights such as artificial lighting, light emitted by digital screens, the light reflections coming from white glossy paper, sunlight and sunlight reflections, and even natural light can cause discomfort for especially sensitive people. All these light sources can become very irritating and trigger very unpleasant symptoms like migraines, headaches, nausea, dizziness, numbness, fatigue, even pain in the eyes, which can cause such discomfort that people feel the need to close their eyes. All of these can be present at the same time or they may vary from person to person, since everyone is different. There are also people that have all of these symptoms preceded by a visual aura and/or a tingling in the ears more commonly known as tinnitus. This is the reason why photosensitive individuals develop over time a fear of light. Where all of this comes from? The problem is not (quite) in your eyes. As counter-intuitive as it may sound, photophobia is not a problem of sensitive eyes but rather it can be defined as a neurological condition. It seems that some photoreceptors located in your eyes generate abnormal electrical impulses that are then transmitted to specific parts of your brain where those abnormal signals can t be processed efficiently and as a result some very unpleasant symptoms are triggered. The most amazing fact is that those photoreceptors in your eyes are not even involved in vision itself, so even blind people can suffer from photophobia. Although there is ongoing investigations about the biological causes of light sensitivity there are no current medications that target photophobia specifically. Also photophobia might be a byproduct of some other underlying health issue like heavy metal poisoning just to give one example. So far, the only side effect free and most efficient way to prevent and even reduce photophobia are PRECISION-TINTED LENSES that can effectively block those parts of the visible spectrum that can trigger those symptoms. Migraines and Photophobia It is a well-known fact that MIGRAINES can be triggered by a wide range of visual stimuli from flickering lights, glare, bright lights, sun reflections to the high energy visible light

6 emanated from computer screen and LCD TV s. So if you have a tendency to develop migraines is quite possibly that too much screen time might be making everything worse, so preventive measures like blocking or diming the screen light might be beneficial. Intolerance to light is one of the features of a migraine and migraineurs tend to show greater light sensitivity than non-migraineurs groups. Studies indicate that 80% to 90% of people have photophobia during a migraine attack. Most likely that s the reason why people cover their eyes when they have a migraine attack to prevent light to enter their eyes. According to England s National Health Service bright and flickering lights boost the levels of certain chemicals in the brain, which then activate the migraine center, Why you should avoid regular sunglasses if you are light sensitive? Constant use of regular sunglasses (even indoor) might appear to be beneficial to light sensitive individuals since they can reduce brightness and they also give temporal relief by reducing the overall amount of light reaching their eyes. There are several caveats with regular sunglasses. First, they cut down all the wavelengths of the visible spectrum in a uniform (not selective) way, meaning they block light waves that are not a problem and still letting in light waves that are problematic and potentially harmful. This means the FILTERING PROPERTIES of the lens are not selective, hence not optimal. Second, with regular sunglasses people can develop over time something that is called DARK ADAPTATION, which means that your eyes eventually get used to the reduced amount of light entering your eyes but eventually making the regular light appear brighter than it is. It s the same effect you experience when you leave a movie theater on sunny day your eyes adjust to being in the dark, so light looks even brighter than before you went into the theater. While most people s eyes readjust to sunlight soon after leaving a movie, people with dark adaptation have extra-heightened light sensitivity at all times. And you don t want this to happen. The solution then is to wear protective eyewear that is specifically designed to block the troublesome wavelengths of light while letting in the part of the visible spectrum that it s not a problem. This way you can maintain visual acuity, avoid dark adaptation and get the therapeutic benefits of those specialized lenses.

7 What is Blue light? We started talking about how most digital devices and modern lighting can emit large amounts of high intensity blue light wavelengths but so far we have not defined it. Blue light is a specific part (415 to 455 nm) of the VISIBLE SPECTRUM and along with UV they are the most harmful light waves to our eyes, and known to cause other health problems. Overexposure to these harmful light waves has short (i.e, eye fatigue, dry eyes, headaches, migraines) and long term vision (i.e. cataracts and macular degeneration) and health effects. What about sunlight? Sunlight contains blue light.but is the constant (and cumulative) exposure to indoor artificial lighting, computer screens, and mobile devices, and it s large emissions of high energy visible blue light that leaves our eyes exposed over time to potential deterioration (and gradual oxidation of the macula). There is growing evidence and research suggesting that the constant and cumulative exposure to blue light can damage retinal cells and eventually lead to long term vision problems such as age-related macular degeneration and cataracts. Is there an evolutionary genetic defect with our eyes that we cannot efficiently process certain parts of the visible spectrum? While high levels of blue light might harm our eyes and reduce our visual comfort, it also have benefits, like helping to regulate our natural CIRCADIAN RHYTHMS and aiding COGNITIVE FUNCTIONS such as alertness, memory and even emotion regulation. There isn t a specific problem with blue light per se. The key concept here is to understand that the problem is high constant and cumulative exposure and the need to protect ourselves when necessary.

8 Fluorescent lights make everything worse For a lot of people artificial lighting is a major concern. And the bad news is that these stressful lights can be found everywhere, from our work offices, retail stores to shopping malls which are the typical places over-loaded with such stressful lights. To make things worse government worldwide are banning the traditional and less harmful incandescent bulbs and replacing them with the more cost-effective artificial lights. Fluorescent bulbs are filled with gas that is excited by electrical pulses, which creates visible light. When the electrical pulses move through the gas, they cause the intensity of light to get brighter and dimmer. While the light output appears to be continuous, this change in intensity makes the light flicker or pulse at a rate that the naked eye can t see (unless the bulb is malfunctioning).

9 Although every person is different and some people seem to tolerate long exposure under artificial lighting without manifesting any major symptom, a lot of people report feeling sick around these type of lights. The problem seems to be the invisible FLICKER that s an inherent part of how fluorescent lights work. Although we cannot see the flicker cause is faster than the eye, that fast paced intermittence is there nonetheless, and our brain reacts to it. Brightness may play a role, but is the exposure to FLICKERING LIGHTS that s the real trigger for migraines, headaches and vision related conditions. The combination of high energy visible blue light coming from your screen plus the flickering artificial lights can be too much of a burden for most of us. Since for many office workers changing or unscrewing the light bulbs or turning off the lights (which in most cases are centralized) may not be possible, using special eyewear can be an effective way to avoid office headaches and to prevent digital eye strain. If you don t feel like wearing precision tinted lenses indoor you can always use screen protectors or software like flux to change your screen white balance (although these are second best solutions since your eyes are still very exposed). Best and worse type of light bulbs The two most common types of LIGHT BULBS are incandescent and artificial fluorescent lights. Unfortunately governments are banning incandescent and switching to artificial lighting based solely on the fact that they are cheaper and consumes less energy. It is discouraging that the direct and hidden economic costs resulting from artificial lighting exposure, like reduced productivity, missed days of work and increased costs in healthcare, are not being considered. INCANDESCENT BULBS are probably the most comfortable and least problematic type of light for most people since they provide a warm light that contains relatively little blue light. They are also the least energy efficient type of lighting, so most governments around the world are banning them out. FLUORESCENT LIGHTS are the most common type of lighting nowadays, from retail stores to offices and shopping malls. They are widely used because they are both energy efficient and inexpensive. The problem with this type of lights is the invisible flicker and the amount of blue-green light they emit. That s the reason why a lot of people get sick around them. WARM WHITE LEDS emit low levels of blue-green light so they are a good option for light sensitive individuals. On the other hand COOL WHITE LEDS emit a high amount of

10 blue-green light so they should be avoided. The problem with LEDs is that some, but not all, have an invisible flicker and it s difficult for consumers to determine if a particular bulb does or not. HALOGENS as incandescent emit very low levels of blue light and the rest of its spectrum is pretty close to daylight, so they are ok if you can handle them being quite bright. Technology and your sleep/wake cycle There is growing research indicating that excessive blue light can also interfere with a person s CIRCADIAN RHYTHMS affecting your sleep cycle. And poor sleep patterns has been shown to lead to chronic health conditions (including depression). Your CIRCADIAN RHYTHMS is a sophisticated internal clock that has evolved over billions of years to biologically adapt your body to the sun, signaling your body to stay awake during lighted hours and asleep during dark hours. The natural 24-hour cycle of light and dark helps maintain precise alignment of circadian biological rhythms, the general activation of the central nervous system and various biological and cellular processes, and entrainment of melatonin release from the pineal gland.

11 The pineal gland secretes the hormone MELATONIN when the sun sets. This hormone is responsible for making you sleepy, making you fall asleep, and staying asleep. Melatonin production is inhibited when you are exposed to blue light, so too much blue light at night tricks your body into thinking it is still daytime disrupting your natural circadian rhythm and keeping you from falling asleep. Hence, excessive screen time at night will most likely decrease the quality of your sleep. Also, disruption of melatonin secretion that comes from nighttime lighting has several potential HEALTH EFFECTS. Among these effects are potential carcinogenic effects related to melatonin suppression, especially breast cancer. Other diseases that may be exacerbated by circadian disruption include obesity, diabetes, depression and mood disorders, and reproductive problems. CONCLUSION Since it is most likely that after reading this we will not put our cell phones down before we go to sleep or that we are not going to shut down our computers two hours before going to bed since this seems to be the new habits of modern life, there are some things we can do to minimize the harmful effects of technology: - Adoption of blue-blocking screen protectors - Changing your lighting at home using low blue light bulbs like orange or amber light bulbs that can minimize circadian disruption, especially at night time - Adjusting your computer s white balance with special software or apps like f.lux - Using specialized eyewear designed to block the blue and green part of the visible spectrum.

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