Blue Light Blocker Guide

You have probably heard that screens give off blue light and that special lenses can filter it. But what is blue light, is it harmful, and do blue light filter lenses actually help? Here is a clear, honest explanation from our optometrists.

What is blue light?

Light that we can see is made up of colours, from red at one end to violet at the other. Blue light sits near the violet end. It has a shorter wavelength and carries more energy than other visible colours, which is why it is sometimes called high-energy visible (HEV) light.

Not all blue light is the same:

  • Blue-violet light (roughly 400 to 455 nm) is the higher-energy part that blue light filter lenses mainly target.
  • Blue-turquoise light (roughly 465 to 495 nm) is useful. It helps set your body clock, keeps you alert in the daytime and supports good colour vision. Good filter lenses let most of it through.

Where does blue light come from?

The sun is by far the biggest source. A few minutes outdoors exposes you to far more blue light than hours in front of a screen. But we now also spend long hours close to artificial sources:

  • Mobile phones and tablets
  • Laptops and computer monitors
  • LED TVs
  • LED and fluorescent lighting

The difference with screens is not the amount of blue light, but how close we hold them, how long we look at them, and how late into the night we use them.

How does blue light affect you?

1. Screen comfort and eye strain

Many people who work on screens all day get tired, dry or aching eyes, headaches or blurred vision by evening. This is called digital eye strain. Its main causes are blinking less while staring at a screen, focusing at a close distance for hours, screen glare, and an uncorrected or out-of-date prescription. Blue light can add to glare and reduce contrast, which some people find uncomfortable.

2. Sleep

Blue light tells your brain it is daytime by suppressing melatonin, the hormone that makes you sleepy. That is useful in the morning, but using bright screens late at night can make it harder to fall asleep. 

3. Neurological Benefits

4. Long-term eye health

You may read claims that screen blue light damages your eyes. Current evidence does not show that the blue light from phones and computers damages the retina. Sunlight is a much stronger source, which is why good sunglasses with UV protection matter outdoors.

How blue light filter lenses help

Blue light filter lenses reduce the amount of blue-violet light reaching your eyes from screens and LED lights. People who wear them most often tell us they notice:

  • More comfortable screen use: less harsh glare from bright white screens and LED lighting
  • Better contrast: text and images can look a little sharper and calmer
  • Easier evenings: less blue light exposure when using phones late at night
  • One everyday pair: with a clear lens, you can wear them all day at work, at home and on the go

If your eyes are often tired or blurry, the most effective first step is an up-to-date prescription. Visit our optometrists which option suits your prescription, or try them at our G-9 Markaz shop, open every day 10am to 9:30pm.

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