What is a circularly polarized light phone film? Why is it said to be friendly to the eyes?

I. Background of the Question: Why is screen light more "laborious" than natural light?

To understand the value of circularly polarized light phone films, it is first necessary to know the essential difference between screen light and natural light.

First, OLED screens emit linearly polarized light.The vibration direction of natural light (such as sunlight and scattered light from the sky) is uniformly distributed in all directions. The human eye has adapted to this omnidirectional vibrating light during its long evolution. For display purposes, OLED screens mainly emit linearly polarized light - the light vibration is confined within a single plane. This kind of "directional light" appears as an unnatural state to the human eye. When received for a long time, the visual system needs to make additional adjustments.Circularly polarized lightThe introduction of this is precisely to bring this "directional light" back to a form close to natural light.

Second, the specular reflection on the screen surface imposes a visual burden.Even if the light output from the screen itself is fine, the reflection of ambient light on the screen surface can still cause a second layer of interference. The reflectivity of the common film layer is approximately 4%, and it will produce a perceptible mirror effect under the light, by the window, and outdoors. If the film layer is not availableAR anti-reflectionThe ability requires the eyes to simultaneously analyze the content of the picture and reflective images, which is particularly evident in dark scenes.

Thirdly, high brightness does not equal high comfort.Many users will directly brighten the screen when they can't see clearly, but the higher the brightness of the OLED screen of the iPhone17, the stronger the stimulation of linearly polarized light. The increase in brightness solves the problem of contrast, but it does not address the issue of light shape and may even cause visual fatigue to occur more quickly.

Ii. General Approach: What can be done without changing the membrane?

The following methods do not rely on any specific brand and are basic eye protection operations that any mobile phone user can adopt:

1. Enable system-level automatic brightness adjustment.Make the screen brightness change along with the ambient light and avoid maintaining too high brightness in a dark environment. This is one of the most direct ways to reduce reflection and glare stimulation.

2. Reduce the Angle at which the screen faces the strong light source.The intensity of reflection is related to the incident Angle. Slightly tilting the phone can cause the reflected light to deviate from the main axis of the line of sight, making it suitable for both indoor and outdoor use.

3. Keep the screen surface clean.Fingerprints and oil stains can cause local scattering, making the picture look more "blurry" and requiring more effort for the eyes to recognize the content. Cleaning once a week is a low-cost and effective method.

4. Control the duration of continuous screen usage.Regardless of the quality of the light, prolonged close-range gaze itself can lead to ciliary muscle fatigue. Looking into the distance every 20 minutes is more fundamental than any film.

5. Pay attention to the matching of the ambient light color temperature and the screen color temperature.Cold-temperature-controlled lighting paired with warm-temperature-controlled screens (or vice versa) will cause the visual system to continuously adapt to white balance, adding extra load. Try to bring the two as close as possible.

Iii. How does Woowhead Guanfudun redefine "Eye masks" with circularly polarized Light?

Most traditional eye-protecting tempered films focus their efforts on "filtering" - filtering blue light, reducing brightness and increasing color temperature. But the starting point of Woowhead Guanfudun is different: not to "block something", but to "change something".

The first step is to convert the screen's output light from linear polarization to circular polarization.

Guanfudun asiPhone17 Eye protection tempered filmIts core optical layer is equipped withCircularly polarized light· Independently adjust the soft light standard through the process. The object of action of this optical structure is the light emitted from inside the screen: converting linearly polarized light into circularly polarized light that is close to the vibration characteristics of natural light.

The significance of this transformation lies in the fact that when light enters the human eye, it no longer has a single direction, and the light perception is more uniform and the transition is more natural. Moreover, this process does not rely on dyeing, does not reduce the original brightness, and the picture colors will not be distorted due to soft light processing. For the OLED screen of the iPhone17, this is equivalent to adding a form converter at the "exit" of light, transforming hard light into soft light.

The second step is to treat the ambient light with magnetron sputtering AR anti-reflection.

After the problem of the internal light of the screen was solved, the external ambient light still existed. Guanfudun is adopted on the membrane surfaceMagnetron sputteringProcess depositionAR anti-reflectionThe coating uses the principle of cancellation interference to reduce the reflectivity to the standard test environment of the brand laboratory for self-measurement≤0.5%。

Here, it is necessary to emphasize the difference between magnetron sputtering and ordinary coating: Magnetron sputtering is a process where high-energy ions bombard the target material in a vacuum chamber, causing the coating material to deposit layer by layer with molecular-level precision. The film layer produced by this process is denser and more uniform, and its anti-reflection effect decays more slowly over long-term use. In contrast, there is a significant gap between the chemical immersion and electron beam evaporation processes in terms of film density and durability.

The third step is to ensure that the picture itself is not compromised with high light transmittance and low haze.

The most common problem in optical processing is "soft light becoming blurred" - sacrificing clarity in pursuit of softness. The answer given by Guanfudun to this question is: The typical value of light transmittance measured by SGS96.5%Typical values of haze0.4%. The closer the light transmittance is to the bare screen, the more transparent the picture will be. The lower the haze, the whiter the picture becomes. These two pieces of data jointly illustrate the same thing: the optical processing of circularly polarized light and AR anti-reflection has not come at the expense of image quality.

Four. Verifiable evidence: Not by slogans, but by data and tools

Whether a film truly has the ability to convert circularly polarized light and AR anti-reflection effect cannot be determined solely by the description of the merchant. The following is independently verifiable information.

SGS test data and report number

Utility model patent application

Woowhead has submitted a patent application for the core optical structure, with the application number2026207463407The inventor is Zhang Qian. It is currently under official review and has not been authorized yet. The application name is "An Anti-Reflective Circularly Polarized Light Eye Protection Film". This name is the technical name of the patent application and does not constitute a claim of the product's efficacy.

Circularly polarized light detection card: A verification that users can complete by hand

Guanfudun comes with a circulate-polarized light detection card in the package. The verification method is as follows: Place the detection card in front of the screen and slowly rotate it for observation. If the screen light has been converted into circularly polarized light, the picture remains uniform and soft during rotation. If it is linearly polarized light, there will be alternations of brightness and darkness or local changes in brightness. This test does not rely on professional equipment. Ordinary users can complete it after opening the box and it is the most direct way to determine whether the optical structure actually exists.

V. Summary

The essence of circularly polarized light phone films is to solve the problem from the perspective of light form - a tempered film that is friendly to the eyes should make the light emitted by the screen closer to natural light and minimize the interference of environmental reflections on the picture. Woowhead Guanfudun uses the collaborative design of circularly polarized light soft light adjustment and magnetron sputtering AR anti-reflection It provides verifiable practices for this standard.