Progressive Lens Design for Motion-Induced Postural Instability
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Solution Overview
Problem
Existing progressive addition lenses (PALs) induce postural instability and motion sickness in some wearers due to aberrations in peripheral regions, with varying sensitivity to motion in different directions.
Innovation Solution
A method and system for determining a progressive lens design by measuring postural instability in mediolateral and anterior-posterior directions, adjusting the distribution of progression profiles on the front and back surfaces based on these measurements, and optimizing the angle of the meridian line to minimize aberrations and discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If progressive lens designs are optimized for different design features and constraints, then visual comfort in specific zones is improved, but postural instability and motion sickness occur in some wearers due to peripheral aberrations
Solution Approach 1:
The patent applies local quality by customizing the progression profile distribution specifically for each wearer based on their individual sensitivity to motion in different directions. Instead of using a uniform lens design, the system measures each wearer's postural instability response to motion in mediolateral and anterior-posterior directions, then tailors the progression profile to minimize aberrations in the peripheral regions that affect that specific wearer. This personalized approach ensures that the lens design adapts to individual physiological characteristics, reducing harmful effects while maintaining visual comfort.
2Device complexity
If limited number of optimized designs are proposed to respect physiological visual functions, then design complexity is reduced, but inability to accommodate individual wearer sensitivity to motion in different directions
Solution Approach 1:
The patent implements dynamics by transitioning from static, pre-defined lens designs to a dynamic, adaptive system that measures each wearer's individual sensitivity to motion and automatically customizes the progression profile accordingly. The system uses real-time measurements of postural instability in different directions to generate personalized lens designs, making the design process flexible and responsive to individual wearer characteristics rather than relying on a fixed set of standardized designs.
Solution Approach 2:
The patent applies parameter changes by modifying the progression profile parameters based on measured wearer sensitivity. The system varies key design parameters such as the distribution of optical power across the lens surface, the angle of the meridian line, and the specific progression curve shape according to each wearer's measured response to motion. This allows the lens design to be precisely adjusted to match individual physiological characteristics, optimizing both visual comfort and minimizing postural instability.
3Reliability
If progression profile is distributed between front and back surfaces, then optical performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies preliminary action by pre-determining the optimal progression profile distribution between front and back surfaces through computational design before manufacturing. The system calculates the ideal configuration based on the wearer's prescription and measured sensitivity characteristics, then uses this pre-planned design to guide the manufacturing process. This approach allows for precise control of the progression profile distribution by establishing the optical design parameters in advance, reducing the complexity and precision requirements during actual manufacturing.
Data Source
AI summary
A method for determining a design of a progressive lens intended to be worn by a future wearer, the progressive lens comprising a front surface and a back surface, at least one of the front surface and the back surface comprising a progression profile on its general spherical shape, said at least one progression profile defining a meridian line extending from a distance-vision point to a near-vision point, said meridian line comprising a vertical portion passing through the distance-vision point and an inclined portion passing through the near-vision point, the vertical portion and the inclined portion forming an angle between them, the method including obtaining first data representative of a first measurement of a first postural instability of the future wearer when seeing a visual pattern moving along an mediolateral direction, and determining a reparation between the first progression profile and the second progression profile based on the first data.