Why is Blue Light Harmful for Your Eyes?

What is blue light anyway?  For starters, sunlight contains 25-30% blue light, so some blue light is natural and healthy.  Artificial light sources emitting blue light include fluorescent light bulbs and LEDs.  LEDs are found in almost every digital device including computer monitors, tablets, readers, and smartphones.

Light is made up of electromagnetic particles that travel in waves.  These wavelengths emit energy and vary in length and strength.  Every wavelength is represented by a different color:  red, orange, yellow, green, blue, indigo, and violet.  Rays on the red end of the spectrum have longer wavelengths and less energy.  Rays on the blue end of the spectrum have shorter wavelengths and more energy.  It is these shorter, higher energy wavelengths that cause concern.

We all know that too much exposure to UV (ultra-violet) light causes painful sunburns.  These rays can also cause sunburned eyes and can lead to cataracts.  Since blue light is next to UV light on the spectrum, it has some harmful effects as well.

The eye is not very good at blocking blue light.  Virtually all visible blue light passes through the cornea and lens and reaches the retina (the inner lining of the back of the eye).  Although more research is needed to determine how much natural and man-made blue light is “too much blue light” for the retina, many eye care providers are concerned that the added blue light exposure from computer screens, smartphones, and other digital devices may increase a person’s risk of macular degeneration later in life (a disease that reduces your central, clear vision and can cause permanent vision loss).

Because 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 eyestrain.  Digital eye strain is a diagnosis that typically includes one or a combination of multiple symptoms, such as tired eyes, shoulder pain, headache, fatigue, eye irritation and pain, blurred or double vision, light sensitivity, tearing, dry eyes, and trouble focusing.

Lastly, blue light plays a major role in melatonin suppression in our brain. Melatonin is released at night and makes us feel sleepy when it is time to go to bed. Melatonin is responsible for keeping our circadian day and night rhythm stable. Too much high energy blue light has been shown to cause disturbances in sleep patterns, specifically difficulty falling asleep at night.

Most of us spend the majority of our waking hours staring at digital screens, whether it’s on the computer at work, our personal cell phone, playing a video game, or just relaxing and watching TV.  Nearly 70% of adults who report regular usage of media devices experienced some symptoms of digital eyestrain. Many did nothing to lessen their discomfort, mainly due to lack of knowledge.

So, what can we do to help reduce visual digital eyestrain and protect our eyes from blue light?  Some strategies to reduce blue light include blue-blocking lenses and blue-blocking coatings.  

Here at Eyes For Life, we offer both TechShield and Prevencia lens coatings which act as both an anti-reflective and blue-blocking coating. Essilor Progressive Addition Lenses and Eyezen  lenses have the blue-blocking protection built into the clear lens. For an extra 10% blocking of high intensity blue-light, you can add TechShield or Prevencia coatings to Eyezen or any Essilor Progressive lenses.

Have questions? Come talk about how blue-blocking technology can help protect your eyes with our friendly and knowledgeable opticians at Eyes For Life.