Blue Light Essentials
What is Blue Light?
- Blue light comes from digital screens (e.g. computers, laptops, tablets, mobile phones, etc.), in addition it is all around us in the daylight
- Blue light is the visible light spectrum with the shortest wavelength and highest energy, similar to ultraviolet rays. Blue light has both benefits and dangers. The light spectrum consists of UV, visible, and infrared light
- The light that can be seen by people (the visible light) accounts for 50% of the light spectrum, whereas UV and Infrared Light are both invisible. These different-colored light rays contain different amounts of energy
- Visible light has a wavelength range in the region of 400 to 760nm, with high energy visible (HEV), light is falling somewhere between 400 - 500nm. It is called high energy visible light because the blue/violet band of the visible spectrum has a particularly high frequency
Facts about Blue light:
- Blue light is present in the daylight. Furthermore, it is emitted from digital screens.
- HEV light rays make the sky look blue: the short-wavelength, high-energy light rays on the blue end of the visible light spectrum, scatter more easily than other visible light rays when they strike air and water molecules in the atmosphere. The higher degree of the scattering of these rays makes the cloudless sky look blue.
- Eyes are not really preventing harmful blue light: anterior structures of the adult human eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. Less than one percent of UV radiation from the sun reaches the retina, when someone is not wearing sunglasses.
- Over-exposure in blue light may increase the risk of macular degeneration. In other words the blue light passes all the way to the retina. Scientific studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina.
- Another issue is the digital eyestrain. As a result of short-wavelength, high energy blue light scatters more easily than other visible light, as it is not as easily focused. Daily exposure to blue light can cause digital eyestrain.