Wavelength-Selective Glass for Myopia Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current window glasses do not effectively suppress the progression of axial myopia by selectively transmitting light in specific wavelength regions while blocking harmful ultraviolet rays, which can cause eye damage.
Innovation Solution
A wavelength-selective transmissive glass with a light transmittance of 1% or more in the range of 315 nm to 400 nm and less than 60% transmittance at 315 nm or less, composed of specific elements like Au, Ag, Sn, and Ti, and a glass matrix of SiO2, Al2O3, MgO, CaO, Na2O, and K2O, designed to transmit light in the 315 nm to 400 nm range while minimizing transmission in the UV range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a glass transmits light in a wide range including UV rays, then visibility and natural light perception are improved, but eye damage from UV radiation and axial myopia progression occur
Solution Approach 1:
The glass spectrum is segmented into different wavelength regions with selective transmittance: high transmittance for visible light (380-780nm) to maintain visibility, while blocking UVB (280-315nm) and selectively transmitting UVA (315-400nm). This segmentation allows the glass to provide visibility while preventing harmful UV radiation from reaching the eyes.
Solution Approach 2:
The glass exhibits different optical properties at different wavelength regions. Specifically, it has high transmittance in the visible region (400-780nm) for good visibility, moderate transmittance in the UVA region (315-400nm) for myopia prevention, and low transmittance in the UVB region (280-315nm) for eye protection. This local quality variation resolves the contradiction between visibility and UV protection.
2Object-affected harmful factors
If a glass blocks all UV rays to prevent eye damage, then UV protection is improved, but the ability to suppress axial myopia progression is reduced
Solution Approach 1:
The UV region is segmented into UVB (280-315nm) and UVA (315-400nm) bands with different transmittance characteristics. The glass blocks UVB rays to prevent eye damage while allowing UVA rays to pass through to suppress axial myopia progression. This segmentation enables simultaneous achievement of both eye protection and myopia suppression.
Solution Approach 2:
The glass composition parameters are optimized to achieve specific transmittance values at different wavelengths. By controlling the content of CeO2 (0.01-5 mass%), Fe2O3 (0.01-5 mass%), and other metal oxides, the glass achieves T(280-315nm) ≤ 60% for UV protection while T(315-400nm) ≥ 1% for myopia suppression, resolving the contradiction between these two functions.
3Adaptability or versatility
If a glass selectively transmits only specific wavelength regions, then wavelength selectivity is improved, but manufacturing complexity increases
Solution Approach 1:
The glass uses a composite composition combining multiple metal oxides (CeO2, Fe2O3, TiO2, SnO2, etc.) with silica base glass. Each oxide contributes to specific wavelength absorption characteristics, and their synergistic interaction achieves the desired spectral selectivity. This composite approach enables complex optical functionality through a relatively simple single-phase glass material, avoiding the need for multi-layer structures.
Solution Approach 2:
The glass composition parameters are systematically optimized to achieve the target transmittance characteristics. By adjusting the content ratios of CeO2 (0.01-5 mass%), Fe2O3 (0.01-5 mass%), TiO2 (0.01-2 mass%), and other oxides, the glass achieves wavelength-selective transmittance without requiring complex multi-layer structures or additional processing steps.
4Adaptability or versatility
If a glass contains multiple metal oxides to achieve wavelength selectivity, then optical performance is improved, but production cost increases
Solution Approach 1:
The glass composition parameters are optimized to achieve the desired optical performance with controlled amounts of expensive additives. CeO2 content is set at 0.01-5 mass% and Fe2O3 at 0.01-5 mass%, which are sufficient to achieve the wavelength-selective transmittance characteristics. This parameter optimization balances optical performance with production cost by avoiding excessive use of rare earth elements.
Solution Approach 2:
The glass formulation incorporates both expensive (CeO2) and relatively cheaper (Fe2O3, TiO2, SnO2) metal oxides. By combining these materials, the patent achieves the desired optical performance while reducing dependence on large amounts of expensive rare earth elements, thereby lowering production costs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The glass effectively suppresses the extension of eye axial length, preventing axial myopia and reducing eye damage from UV radiation, while allowing sufficient visible light transmission for visibility and aesthetic appeal.
Implementation Method 1
a light transmittance T 315 nm or less at a wavelength of 315 nm or less represented by the formula shown below of 60% or less in terms of a plate thickness of 6 mm
Implementation Method 2
a light transmittance T more than 315 nm and 400 nm or less at a wavelength of more than 315 nm and 400 nm or less in the formula shown below of 1% or more in terms of a plate thickness of 6 mm
Data Source
AI summary
The present invention relates to a wavelength-selective transparent glass whereof the light transmittance Tgreater than 315 nm, less than or equal to 400 nm at wavelengths from 315 nm exclusive to 400 nm inclusive, represented by the following equation, is 1% or higher when converted into 6 mm plate thickness, and the light transmittance Tless than or equal to 315 nm at 315 nm or shorter wavelengths, represented by the following equation, is 60% or lower when converted into 6 mm plate thickness. (In the equations, Ak s a weighting coefficient at wavelength k (nm) for calculating T (light transmittance) as defined in ISO-9050:2003, and Tk is a transmittance at wavelength k (nm) for calculating the conversion to 6 mm plate thickness.) Tmore than 315 nm and 400 nm or less=∑k=more than 315400Ak×Tk/∑k=more than 315400Ak T315nm or less=∑k=300315Ak×Tk/∑k=300315Ak