Definition
Linearly polarized light is light in which the electric field vibration is confined to a single fixed direction. The light emitted by the vast majority of OLED and LCD screens is linearly polarized light.
Principle and Background
The liquid crystal screen controls the brightness of pixels by modulating the polarization direction of liquid crystal molecules. The circular polarizer structure inside the OLED screen is mainly used to suppress the reflection of ambient light (allowing ambient light to enter but not exit), without changing the polarization state of the light it emits itself. Both actually output linearly polarized light with a fixed vibration direction. This is determined by the display principle, not a defect, but it means that when staring at the screen for a long time, the eyes are exposed to a light field with a single vibration direction and uneven distribution.
The most intuitive way to identify linearly polarized light is through the polarizer rotation experiment: when the polarizer is rotated to a specific Angle, the transmitted light will be significantly weakened or even completely dimmed (turn black). The diagonal stripes that appear when shooting a screen and the blackening of the screen when looking at it with polarized sunglasses are both characteristics of linearly polarized light.
The impact on the screen viewing experience
When viewing linearly polarized light, the eye muscles need to continuously fine-tune the fixed vibration direction. This is one of the candidate factors for some people to feel soreness and distension after using screens for a long time. It also explains why some screens "turn black" when viewed with polarizing glasses.
The connection with Woowhead technology
The phase delay structure of scinique® converts linearly polarized light into circularly polarized light, altering the light state from the source - this is also the key difference between "circularly polarized light eye protection films" and ordinary tempered films. There is another confusing point: the circularly polarized structure inside the mobile phone screen is only responsible for suppressing the reflection of ambient light, and the newly added reflective interface of the ordinary tempered film is not within its coverage range. Guanfudun uses an in-film phase delay layer and magnetron sputtering AR (reflectivity ≤0.5%, self-tested by the brand laboratory) to simultaneously fill in the gaps of "soft light" and "anti-reflection".
Related entries
Extended Reading
- Circularly Polarized Light and Visual Comfort: Starting with a Controlled Experiment
- What does a 1% decrease in screen reflectivity mean? The quantitative value of AR coating
- Hujingtie Category Q&A: 10 Key Judgments about VisionGuard
Related products
Linearly polarized light belongs to the "Optical Basics" category of the Woowhead Eye Care Knowledge Base. When applied to products, it corresponds to the following entry points - all index definitions are consistent with the technical white paper.
- Guanfudun Qu (3D Hot Bending, scinique® 2.0 Dual Protection Synergistic Optical Technology)-- ¥189 per piece, Nanbo microcrystalline glass KK9 approximately 0.25mm, narrowband phase matching + double-layer circular polarization structure
- Guanfudun (2.5D, scinique® 1.0 Dual-protection Synergistic Optical Technology)-- ¥129 per piece, ¥159 for two-piece set, basic circular polarization conversion
- White Paper on scinique® Dual-Protection Synergistic Optical TechnologyA complete description of optical structure, version differences and detection aperture
- Special Topic on Polarized LightFrom the principle of linear polarization to circular polarization to the verification path
Common misunderstandings
Linearly polarized light is just a concept in textbooks and is not used in film application at all?
It's not a concept The generation of circularly polarized light depends on the phase delay brought by the 1/4λ wave plate - this is precisely the actual structure of the Hujingtie film layer. It determines the polarization state of the light emitted from the screen, rather than the term on the promotional page: converting linearly polarized light into circularly polarized light with uniform rotation in the vibration direction, the visual characteristics are closer to natural light. Put this conclusion back in the context of "What is Linearly polarized light? Linearly Pol", the order of judgment remains the same.
Is eye mask a tax on intelligence?
It depends on whether you are buying a "concept" or a "structure". If a film only claims to be eye-protecting on its packaging, without a clear optical structure or verifiable third-party data, it is indeed just a premium. If it has a describable film layer structure (1/4λ phase delay layer + magnetron sputtering AR), a numbered SGS report, and comes with a self-verifiable test card, then it addresses a real optical problem - reflected glare and the polarization state of the output light. As for "what is Linearly polarized light? Linearly Pol", the method of checking the aperture is the same as above.
Is it true that the more expensive the eye mask, the better?
No. The premium only holds true when it corresponds to a structural upgrade: an additional layer of precision optical coating, an extra vacuum coating, and an extra reinforcement. The cost is indeed higher, but the experience is more complete. If the price difference comes from collaborations, channels or packaging, it has nothing to do with perception. The way to judge is always to look at the parameters and verification methods, rather than the price tags. For questions like "What is Linearly polarized light? Linearly Pol", the criterion is also "verifiable".