WHAT IS BLUE LIGHT?
Blue light makes up part of the electromagnetic spectrum as part of the visible light waves. They are produced in high volumes by our sun and help to boost wakefulness in daylight hours by suppressing a hormone called melatonin. Humans have evolved to become sensitive to these wavelengths to regulate our circadian rhythm, specifically our sleep-wake cycles. Before the invention of artificial light sources melatonin levels would increase after sundown, triggering our bodies to prepare for sleep. However, the emergence of LED lighting has disrupted this system, suppressing rising levels of melatonin into the evening hours. Worryingly, recent evidence shows that this is having a hugely detrimental effect on sleep quality and in turn many facets of our health and well being.
Devices that produce blue light include:
• Mobile phones
• LED bulbs
DOES BLUE LIGHT AFFECT SLEEP?
Recent data shows that we spend on average over 8 hours a day in front of screens. Evening use of blue-light emitting devices can negatively impact sleep quality and with many of us using tablets to read and scrolling through social media in bed, we are affecting our ability to rest properly once we switch off to fall asleep. One study comparing the sleep of people using a tablet to read for 1 hour before bed to another group reading a book for an hour showed a delay in melatonin peak of 3 hours and a reduction in REM sleep by 50% through the night, which is an important phase of the sleep cycle for optimal brain function and mental health. We therefore know that night-time exposure to blue light can affect both quantity and quality of sleep, and certainly compromise our ability to get the recommended 8 hours.
DOES BLUE LIGHT CAUSE DIGITAL EYESTRAIN?
A large amount of research is currently being carried out to determine whether excessive blue light exposure causes problems to vision, but some evidence has suggested that it can cause damage to the retinal cells of the eye. Frequent screen-users commonly complain of eye discomfort and tiredness, as well as headaches. Our lenses also reduce screen glare which helps to further reduce these issues.
IS BLUE LIGHT BAD FOR MY HEALTH?
Along with the health implications of not sleeping enough, there is now increasing evidence emerging that links excessive blue light exposure with a number of health conditions.
• Cardiovascular disease
• Certain types of cancer (breast and prostate)
• Anxiety and depression
WHAT ELSE CAN I DO TO PROTECT MYSELF FROM BLUE LIGHT?
The 20-20-20 rule - look away from your screen every 20 minutes, for 20 seconds and focus on something at least 20 feet away
Try to maintain a distance of 20-28 inches from eyes to screen
Take advantage of setting available on some devices which reduce blue light beyond sundown
Dim your lights at home/ turn off unnecessary lights in the evening
Avoid blue-light emitting devices as much as possible 1 hour before bedtime