Do blue light blocking glasses really work?

Blue light glasses are said to reduce eye strain when using a computer, improve sleep, and protect eye health. You can buy them directly from the store or have them prescribed to you by your eye doctor if you want lenses with correction. But are these glasses effective? Or could it be harmful? Here is the information I found about this matter after studying the available data.

What are anti-blue light glasses?

Blue light blocking glasses, blue light filtering lenses, or blue light blocking lenses are different terms used to refer to lenses that reduce the amount of short-wavelength visible (blue) light that reaches the eyes.

Most of these optician-recommended lenses reduce blue light transmission by 10 to 25%. Standard (clear) lenses do not filter blue light.

There is a wide range of filters. It can be added to eyeglasses or contact lenses. These products are very popular in the market and their popularity is constantly increasing.

However, there is often an additional cost depending on the specific product. But is this extra expense worth it?

Blue light is all around us

Blue light is part of the visible light spectrum with a wavelength between 380 and 500 nanometers.

• Outdoors, sunlight is the main source of blue light.
• Indoors, light sources, such as light-emitting diodes (LEDs) and digital device screens, emit varying degrees of blue light.

The amount of blue light emitted by artificial light sources is much less than that emitted by the sun. However, artificial light sources are all around us, at home and at work, where we spend a significant portion of our time.

A team of researchers from the University of Melbourne, with collaborators from Monash University and City University London, investigated whether the best existing evidence supports the use of blue light-filtering glasses, or whether such glasses are useless, or worse, if possible. Harm your health. To do this, they conducted a study⁽¹⁾ Systematically collect and evaluate all relevant studies.

All randomized controlled studies evaluating blue light filtering lenses in adults were considered. Seventeen eligible studies were identified in six countries, including a total of 619 adults.

Does it reduce eye fatigue?

No benefit has been shown in using blue light filtering lenses, compared to standard (clear) lenses, for reducing eye strain when using a computer.

This conclusion is based on consistent results from three studies that evaluated effects on eye strain over periods ranging from two hours to five days.

Do they help you sleep?

Effects on sleep are inconclusive. Six studies have evaluated the effects of wearing blue light filtering glasses before bed on sleep quality, and the results have been mixed.

These studies focused on people with various conditions, including insomnia and bipolar disorder. Healthy adults were not included in these studies. Therefore, we do not yet know whether these lenses affect sleep quality in the general population.

Does it improve eye health?

No clinical evidence has been found to support the use of blue light filtering lenses to protect the macula (the area of ​​the retina that controls highly detailed central vision).

Can these glasses be harmful?

It was not possible to draw firm conclusions about whether wearing blue light filtering lenses can be harmful compared to standard (non-blue light filtering) lenses.

Some studies describe headaches, low mood, and discomfort associated with wearing glasses. However, people using glasses with standard lenses have reported similar effects.

Some criticism

There are some general considerations in interpreting the study results.

First, most studies covered a relatively short time period, which limits our ability to consider long-term effects on vision, sleep quality, and eye health.

Second, the study evaluated effects on adults. We don't know yet whether the effects are different for children.

Finally, it was impossible to draw conclusions about the potential effects of blue light filtering lenses on many vision and eye health factors, including color vision, because the studies did not evaluate these factors.

What to remember

Overall, the available data are relatively limited and do not allow us to confirm that the use of blue light filtering lenses reduces eye strain associated with using a digital device. It is not known whether these lenses affect the quality of vision or sleep, and no conclusions can be drawn about possible effects on retinal health.

If you have eye strain or other eye or vision problems, talk to your eye doctor. He or she will be able to perform a comprehensive examination of your eye health and vision, and discuss all relevant treatment options.