In today’s world, people are spending more time than ever on devices such as computers, tablets and cell phones. These devices, with the addition of the sun, television screens, LED and fluorescent lighting, give off a harmful high-energy visible blue light. This light can affect both our vision as well as our general health.
High-energy visible blue light makes up the violet to violet-blue end of the light spectrum and can have negative effects on our circadian rhythm and eye health but positive effects on some skin conditions such as acne and psoriasis. Blue light stimulates mental alertness, so using a device at bedtime can waken your brain, causing you to have difficulty falling asleep and making you more tired the following day.
In regards to our eye health, cells at the back of the eye absorb blue light; continuous exposure over time can eventually lead to permanent damage of the retina, the tissue at the back of the eye. Another side effect of prolonged exposure to harmful blue light is digital vision syndrome. Symptoms include dry, burning, watery eyes as well as eyestrain, headaches and blurry vision.
According to the American Academy of Ophthalmology, an excessive amount of daily screen time has been associated with obesity, developmental outcomes, eye development and poor sleep quality in children. The American Academy of Pediatrics advises against screen time with the exception of video chat for children younger than 18-24 months and limiting screen time to one hour or less per day for children older than two. They also recommend no screen time for one hour before bedtime.
When looking at a device or screen, the eyes’ blink rate decreases by 60-65%. Blinking keeps the eye lubricated. The more time spent on a screen, the drier your eyes can feel. Remember to blink! Another recommendation is the 20/20/20 rule with device use. For every 20 minutes of staring at a screen, take a 20 second break and look at least 20 feet away.
There are steps you can take to limit exposure and prevent damage caused by blue light, such as eating a healthy diet rich in carotenoids (lutein and zeaxanthin) as well as omega-3 fatty acids. These nutrients are found in rich-coloured fruits and vegetables such as leafy greens and orange peppers as well as in sardines, salmon, nuts and flax seed. Avoid smoking and diets high in saturated and trans fats. UV protection is another important factor as the sun gives off the highest amount of blue light. Glasses with a blue-filter lens coating are available and are designed to selectively block harmful blue light. Glasses with this coating also help to reduce symptoms associated with digital vision syndrome.
Exposure to harmful blue light from artificial lighting, devices and the sun is inevitable. Factors to take into account include intensity, distance from a device, duration and time of exposure. The combination of a healthy diet, glasses with a blue-filter lens coating and taking advantages of technology’s blue light-reducing apps or Night Shift on your devices will provide you with the most comprehensive protection against harmful blue light. Remember to take regular breaks from devices, to avoid smoking, to protect against sun exposure and to eat a healthy diet!