Progressive Eyeglass Lens Design Using Contrast Sensitivity
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Solution Overview
Problem
Existing eyeglass lenses do not account for individual differences in contrast sensitivity, leading to suboptimal visual performance.
Innovation Solution
Measure contrast sensitivity using at least two eye charts with different spatial frequencies to design customized eyeglass lenses with varying addition powers in progressive portions, incorporating this data into an eyeglass lens ordering and order receiving system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If eyeglass lenses are designed using standard visual acuity evaluation methods, then manufacturing complexity is reduced, but individual differences in contrast sensitivity are not accounted for, leading to suboptimal visual performance
Solution Approach 1:
The patent performs contrast sensitivity measurement using multiple eye charts with different spatial frequencies before lens design. This preliminary measurement action captures individual differences in contrast sensitivity, which then informs the customized lens design process, resolving the contradiction between standardization and personalization
Solution Approach 2:
The patent changes the evaluation parameters from standard visual acuity alone to include contrast sensitivity across multiple spatial frequencies. This parameter expansion enables differentiation of individual visual characteristics, allowing lenses to be optimized for each person's specific contrast sensitivity profile rather than using generic designs
2Reliability
If eyeglass lenses are customized based on individual contrast sensitivity measurements, then visual clarity is improved, but measurement precision requirements increase
Solution Approach 1:
The patent segments the contrast sensitivity measurement into multiple discrete spatial frequency components using different eye charts. By measuring contrast sensitivity at various spatial frequencies separately, the system captures the complete contrast sensitivity profile with high precision, which then guides the customized lens design for optimal visual clarity
Solution Approach 2:
The patent establishes a feedback loop where contrast sensitivity measurement results directly inform lens design parameters. The measured contrast sensitivity data at different spatial frequencies feeds into the design process, creating a closed-loop system that continuously optimizes visual clarity based on individual measurement outcomes
Data Source
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AI summary
Contrast sensitivity of a wearer of an eyeglass lens (10) is measured using a first eye chart and a second eye chart with different spatial frequencies, and the eyeglass lens (10) is designed using a design parameter based on the contrast sensitivity of the wearer. For example, the eyeglass lens (10) is designed such that a distribution of an addition power in a progressive portion of the eyeglass lens (10) becomes high, that is, a refractive power of the progressive portion becomes high as a difference (rate of change) in contrast sensitivity with respect to the different spatial frequencies becomes large.