Variable Refractive Index Layer for Ophthalmic Lens Customization
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Solution Overview
Problem
The existing manufacturing process for ophthalmic lenses requires a large number of semifinished lens models to accommodate individual wearer characteristics, leading to increased production costs and complex stock management, while also necessitating expensive 'free form' machining equipment for complex rear face designs.
Innovation Solution
An ophthalmic lens with a variable refractive index layer is used, allowing for customization by adjusting the refractive index based on wearer measurements, which simplifies the optical base component design and reduces the number of necessary lens models by modifying optical characteristics such as optical power and astigmatism, enabling flexible manufacturing and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large number of semifinished lens models are used to accommodate individual wearer characteristics, then customization precision is improved, but production cost and stock management complexity increase
Solution Approach 1:
The patent applies parameter changes by modifying the refractive index parameter of the lens material to achieve customization. Instead of creating multiple physical lens models with different designs, the invention varies the refractive index parameter (from 1.5 to 1.74) of a single base lens design to accommodate different wearer needs, thereby reducing stock management complexity while maintaining customization precision
Solution Approach 2:
The patent implements universality by creating a single versatile base lens design that can serve multiple customization purposes through refractive index variation. One universal lens model can be adapted to different prescriptions and wearer characteristics by adjusting the refractive index, eliminating the need for multiple specialized lens models and simplifying inventory management
2Manufacturing precision
If complex rear face designs are manufactured using 'free form' machining, then optical performance is improved, but equipment cost and manufacturing complexity increase
Solution Approach 1:
The patent replaces complex mechanical free-form machining processes with a simpler manufacturing approach. By optimizing the front face design and utilizing refractive index variation, the invention achieves superior optical performance without requiring expensive free-form rear face machining equipment, thereby simplifying the manufacturing process and reducing equipment investment
Solution Approach 2:
The patent applies preliminary action by pre-optimizing the front face design and refractive index distribution during the manufacturing process. This preliminary optimization of the front surface geometry and material properties eliminates the need for subsequent complex rear face machining, streamlining the overall manufacturing process
3Ease of manufacture
If the number of semifinished lens models is reduced, then production cost and stock management are simplified, but customization flexibility is worsened
Solution Approach 1:
The patent uses parameter changes (refractive index variation) to maintain customization flexibility with fewer lens models. By varying the refractive index parameter across different batches of the same base lens design, the invention achieves diverse customization outcomes without maintaining large inventories of different lens models, thus reducing production costs while preserving adaptability
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
This approach allows for precise adaptation of lenses to individual wearer needs, reducing the number of required lens models and enabling customization downstream in the manufacturing chain, while maintaining optical performance and comfort, without the need for expensive machining equipment.
Implementation Method 1
at least one layer (2) placed on a face (1a, 1b) of the optical base component (1), said layer being substantially transparent and having a variable refractive index at said wavelength
Data Source
AI summary
An ophthalmic lens (10) comprises an optical component (1) and a layer (2) placed on a face of the optical component (1a). The layer (2) has a variable refractive index and is structured so that a second order derivative of the index with regard to a linear spatial coordinate along the face of the optical component (1a) is greater than a fixed threshold. The layer (2) makes it possible to alter the optical power and astigmatism of the lens (10) with regard to corresponding values only relative to the optical component (1). In the event that the ophthalmic lens (10) is a progressive lens, the layer (2) makes it possible to change an addition, a length of progression and/or a design of the progressive lens.