Ophthalmic Lens Using Regressive and Non-Regressive Elements to Reduce Astigmatism
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Solution Overview
Problem
Conventional multifocal ophthalmic lenses, such as progressive addition lenses, suffer from significant unwanted astigmatism, which compromises vision and reduces the benefits of their vision zones.
Innovation Solution
The design incorporates regressive and non-regressive rotationally symmetric optical design elements, positioned on the same or different lens surfaces, to create a desired optical power profile while exploiting the orthogonal astigmatic vectors of these elements, thereby reducing unwanted astigmatism. These elements can be combined in various configurations to form a progressive addition lens or enhance existing lens designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional multifocal ophthalmic lenses are used to provide multiple vision zones, then the user gains access to different vision zones (distance, intermediate, near), but the lenses produce large amounts of unwanted astigmatism that compromise vision quality
Solution Approach 1:
The patent segments the optical power distribution by using multiple rotationally symmetric optical design elements (RSODEs) with different power profiles (regressive and non-regressive) positioned at different locations on the lens. Each RSODE provides a specific power progression pattern, and their combination creates multiple vision zones while controlling astigmatism through the segmented arrangement and overlapping power distributions.
Solution Approach 2:
The patent applies local quality by assigning different optical characteristics to different regions of the lens. Each RSODE has a specific center location and provides localized power progression tailored to that region's visual demands. The regressive and non-regressive elements are positioned to provide appropriate power distribution in their respective zones while their astigmatic effects neutralize each other in overlapping regions.
2Manufacturing precision
If conventional progressive addition lens design is used to achieve smooth power progression, then optical power transitions between vision zones, but significant astigmatic distortion is generated in the progression zones
Solution Approach 1:
The patent employs asymmetric power distribution within rotationally symmetric elements. Each RSODE has a specific power profile (regressive or non-regressive) that is asymmetric in its power progression pattern. The combination of these asymmetric power distributions creates a balanced overall design where the astigmatic effects cancel out while maintaining smooth power progression through the lens.
Solution Approach 2:
The patent uses the concept of counterweight by positioning regressive and non-regressive RSODEs such that their astigmatic vectors oppose and neutralize each other. The regressive element produces astigmatism in one direction while the non-regressive element produces astigmatism in the opposite direction, creating a counterbalancing effect that reduces overall astigmatic distortion while maintaining the desired power progression.
Data Source
AI summary
Aspects of the present invention provide an ophthalmic lens comprising at least one regressive and at least one non-regressive rotationally symmetric optical design element. The regressive and non-regressive optical design elements can be combined so as to form a desired optical power profile for the lens while simultaneously exploiting the different relative orientation of the astigmatic vectors of the constituent regressive and non-regressive design elements, thereby resulting in reduced unwanted astigmatism. The regressive and non-regressive rotationally symmetric optical design elements can be positioned on different lens surfaces and in optical communication or can be collapsed onto the same lens surface. The regressive and non-regressive rotationally symmetric optical design elements can each contribute to the total add power of an ophthalmic lens. The regressive and non-regressive rotationally symmetric optical design elements can be combined with any other optical design feature positioned on the same or a different surface of the lens.