Progressive Ophthalmic Lens Intermediate Vision Zone Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing progressive ophthalmic lenses often compromise visual comfort at intermediate distances, reducing comfort at far and near distances as well, due to a narrow intermediate distance vision region, especially with increased use of screen-based activities.
Innovation Solution
A progressive ophthalmic lens design that meets an acuity performance criterion by defining specific vision distances with associated acuity loss and area threshold values, using an acuity model to optimize lens power and astigmatism, ensuring increased optical comfort across distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the progressive region is extended to provide broader intermediate distance vision, then the intermediate vision coverage is improved, but the visual comfort at far and near distances deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive power distribution across different zones of the lens. Specifically, it defines precise refractive power ranges for the far distance vision region (0.5D to 2.0D), intermediate distance vision region (1.0D to 3.5D), and near distance vision region (1.5D to 4.0D). This quantitative parameter optimization allows the lens to provide extended intermediate vision while maintaining comfort at other distances through controlled refractive power transitions.
Solution Approach 2:
The patent segments the lens into distinct functional zones: a far distance vision region, an intermediate distance vision region, and a near distance vision region. Each zone is defined by specific refractive power ranges and spatial locations on the lens. This segmentation allows each region to be optimized independently for its specific viewing distance while maintaining overall lens harmony and comfort.
2Area of moving object
If the refractive power progression is accelerated to provide broader vision coverage, then the vision coverage is improved, but the astigmatism and visual quality deteriorate
Solution Approach 1:
The patent implements parameter changes by establishing specific refractive power progression rates and astigmatism control thresholds. The refractive power is controlled to progress within defined ranges (0.5D to 2.0D for far vision, 1.0D to 3.5D for intermediate, 1.5D to 4.0D for near vision), and astigmatism is maintained within ±0.5D to ±1.0D. This controlled parameter progression achieves broad vision coverage while preventing optical quality degradation.
Solution Approach 2:
The patent incorporates feedback mechanisms through computational optical modeling that simulates visual performance across different gaze directions and viewing distances. The design iteratively adjusts refractive power distribution and astigmatism control based on acuity predictions and visual comfort assessments, ensuring that vision coverage expansion does not compromise optical quality.
Data Source
AI summary
A progressive ophthalmic lens adapted to a wearer in given wearing conditions having an addition and fulfilling an acuity performance criterion determined by: defining a set of at least three different vision distances including at least a first vision distance greater than or equal to 4 m, a second vision distance greater than or equal to 0.6 m and smaller than or equal to 2 m and a third vision distance smaller than or equal to 0.5 m, each vision distance being associated with an acuity loss threshold value and an acuity area threshold value, providing an acuity model defining acuity loss as a function of lens power and resulting astigmatism, determining of each vision distance using the acuity model the area of gaze directions for which the acuity loss is below the associated acuity loss threshold value.