Specsavers vs. Alina blue light blocking

Specsavers vs. Alina blue light filter

Interest in blue light glasses has grown significantly in recent years, partly due to the intensive use of digital screens in work and private situations. Opticians such as Specsavers offer glasses with a blue light filter, while specialist brands such as Alina focus on a higher degree of blue light reduction. This article compares both approaches based on the technology used, the degree of blue light blocking, and practical applicability.

Disclaimer: This comparison is not intended to criticize or undermine the performance of one product over another. The purpose of this article is solely to provide objective information so that readers can make an informed choice based on their own intended use.

Blue light and its impact on the human body

Blue light is part of the visible light spectrum and is in the wavelength range between 380 and 520 nanometers. This light plays an important role in alertness and cognitive performance during the day. At the same time, scientific studies show that excessive exposure to blue light (especially in the evening) can disrupt melatonin production and the circadian rhythm (Chang et al., 2015).

Research by Harvard Medical School (2020) shows that exposure to blue light in the evening hours has a stronger effect on the biological clock than other light frequencies, which can result in poorer sleep quality and longer sleep onset times. In addition, blue light is associated with digital eye strain during prolonged screen use (Rosenfield, 2016).

Want to learn more about the effects of blue light on the body? Discover our free e-book.

Blue light glasses from Specsavers and reflection technology

Blue light glasses from Specsavers, Ace & Tate, and others typically use reflection technology. This involves applying a thin coating to the transparent lens that reflects some of the blue light. These types of glasses are usually transparent and have minimal impact on color perception.

Comparative research into clear-lens blue light coatings shows that these types of filters block an average of 10 to 20 percent of blue light, depending on the specific coating and wavelength range (Leung et al., 2017). In practice, this amounts to an average blockage of approximately 15 percent. Specsavers and other companies mentioned do not usually provide detailed transmission curves, which limits the possibility of making an exact comparison. But transparent glasses that block 100% of blue light? They don't exist. 

A significant disadvantage of reflection technology is that the filter layer is located on the outside of the glass. This means that its effectiveness can diminish over time due to wear and tear, cleaning, and daily use. Furthermore, the filtered blue light is not absorbed but reflected, which limits the actual reduction reaching the eye.

Alina blue light glasses and absorption nano-technology

Alina's blue light glasses use absorption nanotechnology. Instead of a surface coating, the blue light is absorbed into the lens material itself (and converted into imperceptible heat). This effectively removes the light from the spectrum before it reaches the eye.

Alina's daytime glasses block an average of approximately 35 percent of blue light. This level of blocking is significantly higher than that of standard reflective coatings and remains stable throughout the lens's lifetime, as there is no wear-sensitive coating.

*Alina's red evening glasses block 99.9%, but that's not a fair comparison. Transparent or yellow lenses are also not suitable for evening use, as they let too much light through. 

Absorption-based filters are considered in the literature to be more effective than reflective filters when the goal is to reduce total exposure to blue light (Lin et al., 2019). In addition, this technology prevents unwanted reflections toward the eye and the environment.

Why we chose daytime glasses with 35% blue light absorption

When developing our everyday glasses, we deliberately chose an approach that is suited to prolonged screen use during the day. Many fully transparent blue light glasses focus primarily on filtering the extreme blue-violet part of the spectrum, typically between 380 and 415 nanometers. This choice minimizes visual changes, but leaves a large part of the biologically and visually relevant blue light unaffected.

We have therefore opted for daytime glasses that absorb approximately 35% of blue light and actively filter it in the range from 380 to 455 nanometers. This broader spectrum covers the part of blue light that is dominant in modern screens and lighting. By using absorption technology, this light is absorbed into the lens material itself, rather than being reflected, ensuring stable performance in daily use.

We believe this configuration offers the best balance between noticeable visual comfort and natural color perception during the day. The purpose of these daytime glasses is therefore not to block blue light completely, but to reduce excessive exposure in a controlled and sustainable way during work and other screen-intensive activities during the day.

Limitations of blue light glasses for evening use

Although blue light glasses are often presented as a general solution, several studies show that glasses with low to moderate blue light blocking are insufficient to protect melatonin production in the evening. Burkhart and Phelps (2009) demonstrated that complete blocking of the blue light spectrum only had a significant impact on sleep quality.

It follows that tra are primarily suitable for use during the day and when working at computer screens, but not for evening or nighttime use. This distinction is often not made sufficiently clear in commercial communications.

Clip-ons as a practical alternative for eyeglass wearers

For people who already wear prescription glasses, an integrated blue light coating entails additional costs and limitations. The coating is permanent, susceptible to wear and tear, and cannot be adjusted to the time of day.

Clip-on solutions, such as those offered by Alina, provide a flexible alternative. They allow users to easily switch between blue light filter and no blue light filter, without having to purchase additional glasses or rely on a permanent coating. From a user perspective, this is more in line with the scientifically proven distinction between daytime and evening exposure to blue light.

Conclusion

A comparison between blue light glasses from Specsavers and Alina shows that the technology used makes a significant difference depending on your goal. Reflection technology results in a limited blue light reduction of approximately 15 percent and is primarily focused on visual comfort. Absorption nano-technology, as used by Alina daytime glasses, offers a higher and more sustainable blockage of approximately 35 percent and reduces overall exposure to blue light more effectively.

However, for evening use, neither solution offers sufficient protection against disruption of the circadian rhythm;complete blue light blocking is necessary for this. An informed choice of blue light glasses therefore requires an understanding of both the technology and the intended time of use.