Blue Light, Melatonin and Sleep
You have probably heard about the whole blue light, melatonin and sleep thing.
So what is it all about?
Research found that short wave blue light inhibits the production of melatonin, a hormone that helps with quite a few functions in our bodies. One of them is the sleep cycle.
Greenlight is right next to blue light on the visible light spectrum. After 6.5 hours of exposure of both, blue light inhibited melatonin secretion twice as much as green light did. With this much exposure of blue light, the circadian rhythm (pre-programmed cycle of 24 hours controlled by amount of dark and light we’re exposed to) shifted by up to 3 hours.
Where does it come from?
Most probably you’re reading this on you’re cellphone right now which is one of the most popular short blue light emitters.
These are some of the most common emitters.
- LED Lights
- Desktop Monitors
- Laptops
- Smartphones and Tablets
- Hand-Held video games
- LED TV’s
But in today’s day and age, it is impossible to avoid these sources completely to remove this short waved blue light from our lives.
So what is the real issue with short waved blue light?
Blue light is surely good for us during the daytime because it elevates our alertness levels, but it is certainly not good for us at night time. As mentioned previously, short blue light stops the production of melatonin to up to 3 hours after exposure. This means that after 3 hours that you stopped with the device use, there is still no production of melatonin for up to 3 hours.
Some professors doing research believe that light at night and decreased levels of melatonin, are carcinogenic and are strongly related to breast- and prostate cancer. Other researchers also believe there is a link between the disruption of the circadian rhythms and obesity and diabetes. With the suppression of melatonin, there is a negative impact on physiological processes like sleep, thermoregulation, blood glucose and blood pressure.
Our eyes are responsible for this. They detect light levels and colours and send the information to the hypothalamus. Here the hormones like cortisol are produced to wake us up in the morning and melatonin and make us sleepy at night.
What to do?
Since our eyes are detecting these light levels and intensities, we should change the kind of information our eyes get.
Some helpful tips include:
- Reduce exposure to blue light 30 – 60 minutes before bedtime. This means, no TV, Tablets, Phones and Computers.
- Dimming the devices or switching to night mode.
- Wearing blue protective eyewear.
Does a blue light blocker really help?
A study done by the University of Toronto found that there was more production of melatonin for individuals who wore Blue Light Filtering or Blocking eyewear, than those who did not at night.
So to answer your question, yes it does.
Ask your optometrist about Blue Light Filtering lenses when getting your new pair of Spectacles.