Progressive Lens Power Smoothing for Wider Clear Vision
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Solution Overview
Problem
Existing progressive power lenses often cause discomfort due to a narrowed clear vision area in the horizontal direction, particularly for individuals with significant third-order aberrations or those transitioning between near and far vision.
Innovation Solution
A method to determine a progressive power lens design by smoothing the power distribution in the horizontal direction to reduce third-order aberration and expand the clear vision area, while maintaining the basic design as much as possible, using parameters such as third-order aberration, line of sight movement, and sensitivity to aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the power distribution of the progressive power lens is smoothed in the horizontal direction to reduce third-order aberration, then the clear vision area is expanded in the horizontal direction, but the amount of astigmatism on the principal meridian increases
Solution Approach 1:
The patent applies parameter changes by modifying the power distribution characteristics of the lens through horizontal smoothing. This changes the optical parameters to reduce third-order aberration and expand the clear vision area, while accepting a trade-off in increased astigmatism on the principal meridian. The smoothing process alters the power distribution parameters horizontally while maintaining vertical progression.
Solution Approach 2:
The patent applies local quality by differentiating the treatment of different regions of the lens. The power distribution is smoothed specifically in the horizontal direction while maintaining the progressive power change in the vertical direction. This creates different optical qualities in different regions: reduced aberration in the horizontal clear vision areas while preserving the near-to-far transition in the vertical meridian.
2Ease of operation
If a conventional progressive power lens design is used, then the lens provides basic progressive power correction, but the clear vision area is narrowed in the horizontal direction causing discomfort
Solution Approach 1:
The patent modifies the conventional lens design by changing the power distribution parameters through horizontal smoothing. This parameter change expands the clear vision area horizontally, providing more comfortable viewing for the subject while maintaining the progressive power correction function.
Data Source
Figure 1A~1B
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AI summary
There is provided a method for determining a progressive power lens, the method including: determining a necessity for expanding a clear vision area for a subject wearing a progressive power lens; and when it is determined that the subject requires expansion of the clear vision area in a horizontal direction, selecting a design of the progressive power lens in which a power distribution of the progressive power lens is smoothed in the horizontal direction to reduce third-order aberration in the horizontal direction around a principal meridian of the progressive power lens and the clear vision area is expanded in the horizontal direction.