“All you need to know about BLUE LIGHT”


Before the pandemic, we already live in a digital world. According to a survey about time spent per day on the internet (Source: Global Web Index, Q2 & Q3 2017 of internet users aged 16-64), Philippines ranked second with an average time spent of 9 hours and 29 minutes and ranked first for time spent on social media with an average of 3 hours and 57 minutes per day. For the third year in a row, Filipinos spend the highest amount of time on social media everyday. These figures have exponentially increased during the enhanced community quarantine.

During these challenging times, our children’s education is compromised. But our DepEd Secretary Leonor Magtolis Briones has been working hard to make sure learning will continue but through an alternative online learning method that includes online learning and offline methods (take-home readings and activities). Meaning, most of the children will be exposed to digital devices. These devices can emit high levels of short-wavelength visible light (blue region in the light spectrum – roughly 380 to 500nm).

Studies show that exposure to the visible blue light will cause eye problems like digital eyestrain, dry eyes, headache, and potentially harming the human retina (Wu J, Seregard S, Spangberg B, OskarssonM, Chen E, 1999). Children may be at higher risk for blue light retinal damage than adults (Boettner EA, Wolter JR. T, 1962). Cellular phone, tablet, and personal computer use before bedtime can delay sleep onset, degrade sleep quality and impair alertness the following day (Chang AM, Aeschbach D, Duffy JF, Czeisler CA, 2015). But research says 63% of adults do not know that electronics emit high-energy visible (HEV) or blue light.

So, do we need to protect our eyes from harmful blue light? Definitely YES! I recommend you at least to have an annual visit to your friendly Optometrist for a comprehensive eye exam or CEE.

Our eyes need protection from ultraviolet/UV (380-200nm) and Blue Light (380-500nm) since they are everywhere. Exposure to these lights has its benefits. In moderation, UV rays help the body manufacture adequate amounts of Vitamin D. At the same time, the good blue light triggers the suppression of melatonin in the brain, keeping us awake. It tells us when we are tired or should be awake, meaning it regulates circadian rhythm.

Since UV light contains more energy than blue light, it is absorbed by the cornea (clear front surface of the eye) and crystalline lens, limiting exposure to the retina (innermost layer of our eyes). However, all visible blue light passes through the cornea, lens and reaches the retina. It is where there could be potential risks. As for children, the risk may be higher with retinal damage than adults. The juvenile lens absorbs less short-wavelength light than the adult lens allowing more blue light to reach a child’s retina (BoettnerEA, Wolter JR. T,1962). But there is no clinical evidence at present that links blue light exposure from digital devices to any eye disease.

What concerns us Optometrists are the potential effects of overusing these digital devices. It could lead to Myopia or nearsightedness, experience asthenopia (dry eye, digital eyestrain, uncorrected refractive errors such as astigmatism, binocular vision, and musculoskeletal problems), and photo-oxidative damage to the macula. I believe that appropriate treatment is individualized and science-based.

Are digital devices safe for children? With proper eye protection, discipline, and guidance, it is all right. A wise practice of taking a break every 20 minutes, by looking far at 20 feet away for 20 seconds, not forgetting to blink and observing visual ergonomics is highly recommended. Therefore, visiting an Eye Care Professional, especially this month of August a Sight-Saving month, for a comprehensive eye exam is vital since there are tests to be conducted for us to detect such eye problems.