Light is made up of electromagnetic particles that travel in waves. The shorter the wavelength; the higher the energy. The length of the waves is measured in nanometres (nm). Every wavelength is represented by a different colour, and is grouped into the following categories: gamma rays, x-rays, ultraviolet (UV) rays, visible light, infrared light, and radio waves. Together these wavelengths make up the electromagnetic spectrum. However, the human eye is sensitive to only one part of this spectrum: visible light. Visible light is that part of the electromagnetic spectrum that is colours: violet, indigo, blue, green, yellow, orange and red-VIBGYOR.
Blue light surrounds us and has a very short wavelength, and so produces a higher amount of energy. It can have harmful effects to our eyes and sleep. It is of two types blue violet and blue turquoise. Blue violet (415nm to 455nm) is the harmful light emitted from the digital devices whereas the blue turquoise (456nm to 495nm) is the beneficial light.
Blue light is everywhere.
The largest natural source of blue light is sunlight. In addition, there are many other artificial sources:
Blue light exposure you receive from screens is a concern because of the close proximity of the screens and the length of time usually spent looking at them. 1in10 of India's internet population is a Hyperconnected Consumer, spends 6 hours daily on smartphone and more than half the time on communication and social media. By 2020, 90% of indoor lighting expected to be LED/CFL-sources of harmful BLUE VIOLET LIGHT. Because of their wide-spread use and increasing popularity, we are gradually being exposed to more and more sources of harmful blue violet light and for longer periods of time.
Most of us spend most of our waking hours staring at digital screen, whether it's the computer at work, our personal cell phone, playing a video game, or just relaxing and watching TV. Computer vision syndrome (CVS) is the term used to describe the conditions resulting from the use of today's popular electronic gadgets. Early research shows that too much exposure(>6 hours) to harmful blue violet light could lead to CVS symptoms such as :
Eye strain 
Headaches 
Eye fatigue 
Blurred vision 
Disturbed sleep These symptoms are caused due to long hours sitting in front of a computer screen or other electronic device, thereby affecting learning, productivity and eventually the Quality of life.
Our eyes' natural filters do not provide sufficient protection against blue light rays from the sun, let alone the blue light emanating from these devices or from blue light emitted from fluorescent-light tubes. Prolonged exposure (>6 hours) to harmful blue violet light may cause retinal damage and can lead to loss of vision.
We all do.
Everyone needs to take precautions against the effects of harmful blue violet light. Whether we work in an office or play in the sun; watch televisions for entertainment, spend hours staring at a computer screen or texting on our cell phones, we are all being exposed to harmful blue violet light.
Adults are susceptible too. 63% of adults (DO NOT KNOW) electronics emit harmful BLUE VIOLET LIGHT Adults spend on average 9.5 hours in front of a screen. They are using digital devices more and more in both their personal and professional lives.
By keeping in mind a few simple ways to protect the eyes, we can take pleasure in knowing that our eyes will last much longer than our smartphones, tablets and computers.
Remind yourself to blink more often. Staring at a digital screen can affect the number of times you blink, causing eyes to dry.
Follow the “20-20-20 Rule” - every 20 minutes, stare at something at least 20 feet away for at least 20 seconds. This exercise engages your distance vision and helps the eye to "reset."
Changing your digital devices background colour from bright white to cool gray is a simple tip to reduce digital eye strain.
Avoid using digital devices 30 to 60 minutes prior to bed.
Those who smoke are up to 4 times more likely to go blind in old age. If you are a smoker, make a resolution to kick the habit.
Clean Your Screen. A dust-free, smudge-free screen helps reduce glare.
If you face any computer vision syndrome symptoms, consult your doctor.
Take medicines as recommended by your physician.