Multifocal Ophthalmic Lens Narrow Transition Regions
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Solution Overview
Problem
Multi-focal lenses suffer from significant distortion in transition regions, particularly in lower areas, which can cause visual difficulties and discomfort for wearers, and have limited reading regions, making them difficult to use effectively.
Innovation Solution
A multifocal ophthalmic lens design with narrower transition regions between focal areas, allowing for a wider reading region without extending into lower areas, featuring a progressive region that smoothly transitions between long-distance and short-distance focus areas, and optionally including a third region for long-distance viewing with reduced distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the lens includes traditional transition regions between focal areas, then the lens can provide multi-focal vision, but significant distortion occurs in these transition regions causing visual difficulties
Solution Approach 1:
The patent extracts and eliminates the traditional transition regions that cause distortion, creating a lens design where focal regions are directly adjacent to each other without intermediate transition zones. This is achieved by defining a first region with first focal properties and a second region with second focal properties that are positioned to be adjacent, removing the harmful transition areas while maintaining multi-focal functionality.
Solution Approach 2:
The lens is segmented into distinct focal regions (first region for first focal distance, second region for second focal distance) with clear boundaries. This segmentation allows each region to be optimized for its specific focal function without the distortion-prone transition zones found in traditional progressive lenses, enabling abrupt but controlled focal transitions.
2Ease of operation
If the reading region is made wider to improve usability, then reading comfort increases, but the region extends into lower areas where distortion occurs
Solution Approach 1:
The patent removes the harmful lower regions from the reading area by defining the second region (reading region) with specific boundaries that exclude the lower portions of the lens where distortion occurs. This allows the reading region to be optimized for width and comfort while preventing extension into distortion-prone areas.
Solution Approach 2:
Different regions of the lens are assigned different focal properties and boundaries tailored to their specific functions. The reading region is defined with specific lateral boundaries that prevent extension into lower distortion areas, while other regions maintain their own optimized boundaries, creating locally optimized zones for different visual tasks.
3Object-affected harmful factors
If transition regions are made narrower to reduce distortion, then visual quality improves, but the reading region becomes narrower
Solution Approach 1:
By eliminating traditional transition regions entirely and making focal regions directly adjacent, the patent removes the source of distortion without needing to narrow transition zones. This extraction approach allows the reading region to maintain its full width without being constrained by narrow transition zones, resolving the contradiction between distortion reduction and reading region width.
Data Source
AI summary
In one aspect, the invention is directed to a multifocal ophthalmic lens having a first region having first focal properties, and a second region having second focal properties and including a progressive region. The second region may further include, for example, a portion that is a reading region. The second region has two side edges and there are first and second transition regions between the first region and the side edges of the second region. The transition regions each have a width that is less than a selected width. This gives the lens designer more freedom to provide a wider second region without extending into lower left and lower right regions of the lens.