Blue light: How to get protection from eye damage
Visible light is much more complex than you might think.
Stepping outdoors into sunlight; flipping on a wall switch indoors; turning on your computer, phone or other digital devices — all of these things result in your eyes being exposed to a variety of visible (and sometimes invisible) light rays that can have a range of effects.
What is blue light?
Sunlight contains red, orange, yellow, green and blue light rays and many shades of each of these colours, depending on the energy and wavelength of the individual rays. Combined, this spectrum of coloured light rays creates what we call “white light” or sunlight.
Without getting into complicated physics, there is an inverse relationship between the wavelength of light rays and the amount of energy they contain. Light rays that have relatively long wavelengths contain less energy, and those with short wavelengths have more energy.
Rays on the red end of the visible light spectrum have longer wavelengths and, therefore, less energy. Rays on the blue end of the spectrum have shorter wavelengths and more energy.
Too much exposure to UV causes a painful sunburn — and even worse, can lead to skin cancer. But ultraviolet radiation, in moderation, also has beneficial effects, such as helping the body manufacture adequate amounts of vitamin D.
Blue light generally is defined as visible light ranging from 380 to 500 nm. Blue light sometimes is further broken down into blue-violet light and blue-turquoise light.
Where does Blue Light come from?
Sunlight is the main source of blue light and being outdoors during daylight is where most of us get most of our exposure to it. But there are also many man-made, indoor sources of blue light, including fluorescent and LED lighting and flat-screen televisions.
Most notably, the display screens of computers, electronic notebooks, smartphones, and other digital devices emit significant amounts of blue light. The amount of HEV light these devices emit is only a fraction of that emitted by the sun. But the amount of time people spend using these devices and the proximity of these screens to the user’s face have many opticians and other health care professionals concerned about possible long-term effects of blue light on eye health.
What are the effects of 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.
The fact that blue light penetrates all the way to the retina is important because laboratory studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina. This causes changes that resemble those of macular degeneration, which can lead to blurred vision, headaches, and even permanent vision loss.
Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. When you’re looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual “noise” reduces contrast and can contribute to digital eye strain.
What can we do to reduce blue light?
If you are using your phone constantly — especially if you use it primarily for texting, emailing and web browsing — a convenient way to reduce your blue light exposure is to use a blue light filter.
These filters are available for smartphones, tablets, and computer screens and prevent significant amounts of blue light emitted from these devices from reaching your eyes without affecting the visibility of the display. Some are made with thin tempered glass that also protects your device’s screen from scratches.
Another option is to use a blue light filter that is built into your device. This is a great way to eliminate the amount of blue light, and it’s free. Not all devices will have this feature built-in, so have a read through these useful step by step guides, ‘How to use blue light on your phone’ and ‘How to use your blue light filter on your PC or Mac’.
Computer glasses also can be helpful to reduce blue light exposure from computers and other digital devices. These special-purpose glasses are available without an eyeglass prescription if you have no need for vision correction or if you routinely wear contact lenses to correct your eyesight.
Blue Light filtering glasses can be found online for a fairly good price (around £15-£30), an example of one retailer can be found in the link below:
We hope this helps you with the understanding of blue light and resolving the side effects that can be brought on by it.