As your Optometrist, I recommend blue light filters on glasses for all of my patients. I personally wear lenses with blue light filters. Blue light has been in the news quite often recently and doctors are just now beginning to understand the true impact of its exposure. Not unlike most people, I personally use electronics between six and eight hours per day. I use my phone and laptop extensively during the day and often watch some television in the evening. When I am using these electronic devices, I try and wear my glasses with blue light filters as much as possible.
So what exactly is blue light and why should we be concerned about it? Blue light is a color in the “visible light spectrum” that can be seen by the human eye. Light is made up of electromagnetic particles that travel in waves. These waves emit energy, and range in length and strength. The shorter the wavelength; the higher the energy. Every wavelength is represented by a different color, and is grouped into the following categories: gamma rays, x-rays, ultraviolet (UV) rays, visible light, infrared light, and radio waves. As humans, we are most sensitive to visible light. Many studies are now suggesting that, over time, exposure to the blue end of the light spectrum could cause serious long-term damage to your eyes. Some studies also suggest that blue light disrupts your natural sleep cycle (circadian rhythm) and that consistent disruption to sleep cycles has been linked to various cancers.
Blue light is found indoors. Blue light is found outdoors. Blue light is everywhere! Sunlight is the main source of blue light, and being outdoors during daylight is where we get most of our exposure to it. However, there are also many man-made, indoor sources of artificial blue light, including fluorescent and LED lighting, televisions, smart phones and computers. Our eye’s natural filters don’t provide enough natural protection to blue light. This is why many of us experience eyestrain, headaches and physical and mental fatigue from spending too much time in front of our digital devices.
Here are some key recommendations for limiting your blue light exposure:
- 20-20-20 Breaks: Every 20 minutes take a 20 second break and look at something 20 feet away
- Increase your text size and reduce your screen brightness, some devices, including many smart phones have options to adjust the lighting in the phone settings
- Ensure that devices are not too close to your eyes
- Limit the amount of time you spend in front of electronics screens
- Limit your usage of electronic devices two hours prior to bedtime, it is best to avoid having digital devices in the bedroom
- Ophthalmic lenses with a special coating are designed to filter out blue light. It is not required to have a prescription in your glasses in order to have lenses with a blue light filter
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The amount of HEV light these digital devices emit is only a fraction of that emitted by the sun. However, the danger is due to the excessive amount of time people spend using these devices and also to the proximity of these screens to our faces.
The fact that blue light penetrates all the way to the retina (the inner lining of the back of the eye) 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 and cataracts, which can lead to 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.
A newly conducted study by École d’Optométrie from the University of Montreal found that:
- Wearing a lens treated with a blue-light filter coating helped reduce symptoms of eyestrain by half during prolonged computer exposure.
- After wearing a lens treated with a blue-light filter coating, people with symptoms of eyestrain due to prolonged computer exposure felt a significant improvement of the following symptoms: dry eyes, sticky eyes, and the feeling of grittiness or “sand” in the eye.
- They also reported a trend of the overall vision and improved visual performances in situations of low contrast.
If you have any other questions about blue light or limiting exposure to blue light emitting devices, please call us or ask during your next eye examination.
Diana Ciobanu OD