Mar 23 , 2021

Syed Mahmud

Screen Time and Blue Light

What Is Blue Light?

Light consists of several different wavelengths of color (violet, blue, cyan, green, yellow, and red, ranging from 380 nanometers to 800 nanometer).  The shorter the wavelength, the more energy it emits and the more visible it is.  Since blue is the second shortest wavelength on the color light spectrum, it emits a lot of energy.

Blue light can be found everywhere because our primary source of it comes from sunlight and the outdoors. Other common sources include LED lights, phones, televisions, other screens, etc.   Its main functions are to help us stay alert, boost memory and reaction times and regulate the body’s circadian rhythm.


The Health Risks of Too Much Blue Light 

Our eyes are not good at blocking out blue light because it passes through the cornea and lens and penetrates to the retina.  The retina houses color-sensitive cells which can be damaged by too much blue light exposure and may potentially lead to eye strain and vision damage over a long period of time.   The extra strain prompts us to hunch over more while looking at our screens, leading to kyphosis (a forward curvature of the spine).

Additionally, because it is vital to the regulation of our circadian rhythm to keep us awake, too much blue light from screen time exposure suppresses the production of melatonin (the hormone responsible for helping us relax and fall asleep).


How Do I Limit the Negative Effects of Blue Light?

  • Use the dark mode option on your devices
  • Rest your eyes and give them a break from screen time every so often
  • Limit screen time 2-3 hours before going to sleep