BLOG: What is blue light, and why should I care?
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Blue light sits close to the ultraviolet part of the electromagnetic spectrum. These wavelengths are very short in length and carry a lot more energy in them.
Short wavelength light, such as blue light, can cause photochemical damage to cells and their DNA; therefore, every time you are exposed to blue light, your cells/tissues are at risk of being damaged, leading to cell death and inducing retinal damage in the eye.
Every minute you spend exposing your eyes to blue light increases the chances that you will do damage to your eyes. In our eyes, we have natural sunglasses that help block some of the blue light from entering. This is done by the macular pigments in our eyes, lutein and zeaxanthin, which are antioxidants that work by neutralizing free radicals created by blue light.
There are many different sources of blue light, with the sun being the biggest source of them all. However, as technology advances have occurred over the years, digital devices such as phones, tablets and LED lights have increased the amount of blue light we are exposed to on a daily basis. The amount of exposure we receive from these devices is what we call low intensity. This means the probability of damage is lower and therefore takes longer for the damage to accumulate.
We can help top up the body’s ability to protect against blue light damage by increasing the amount of lutein and zeaxanthin in our body. This can be done by increasing the amount of dark and brightly colored vegetables and fruits in our diet. We can also take steps to reduce our screen time, and using lights that have a lower kelvin rating (eg, 2,700 K) will reduce the amount of blue light in the work environment and home space. Reducing blue light decreases the light that is scattered most, decreasing glare and increasing contrast, thereby improving image quality and reducing eye fatigue. This can be achieved by using blue light blocking screen protectors and glasses such as the FDA-certified Ocushield products.
In February 2021, a U.S. survey of 2,028 people aged 18 years and older found respondents spend an average of 5 to 6 hours per day on a smartphone. This did not include work-related smartphone use. Smartphones now have the ability to show you on average how long you spend on your phone each week.
Blue light and the body
Blue light is not just the new buzzword for the year or a new health kick bandwagon that people are jumping on. Blue light is important for many functions in the body, such as sleep. Blue light regulates the circadian rhythm, which is the body’s natural sleep circle. By being exposed to blue light during the day, this helps regulate the body’s sleep cycle and promotes the production of melatonin when it comes to nighttime. However, with the use of devices such as laptops and phones increasing, even late into the night, the body’s circadian rhythm becomes disrupted. By increasing the amount of blue light exposure before bed, the body’s ability to produce melatonin becomes impaired, therefore leading to problems sleeping and daytime sleepiness.
Blue light boosts alertness, helps memory and cognitive function, and elevates mood. Studies have shown concerns that not enough exposure to sunlight in children could affect their growth and development of their eyes and vision. Early studies also showed that reduced blue light exposure could contribute to the increase of myopia.
References:
Average time spent daily on a smartphone in the United States 2021. https://www.statista.com/statistics/1224510/time-spent-per-day-on-smartphone-us/. Published Feb. 25, 2022. Accessed March 30, 2022.
Chang AM, et al. Proc Natl Acad Sci U S A. 2015;doi:10.1073/pnas.1418490112.
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