Segmented Contact Lens Optics to Reduce Halos in Myopia Control
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Solution Overview
Problem
Conventional contact lenses for myopia and presbyopia correction can cause unwanted visual side effects such as halos around images and improper use of additional focus, and existing dual-focus lenses for myopia progression management are inefficient for young subjects.
Innovation Solution
A contact lens design featuring an optic zone with a series of arcs having increasing radial curvature power and tilted arcs to converge light rays to a point in front of the retina, combined with a peripheral zone for mechanical support, reducing unwanted visual effects and enhancing image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If annular add power regions are used to provide myopic defocus, then myopia progression is slowed, but unwanted visual side effects such as halos and rings appear
Solution Approach 1:
The lens is divided into multiple discrete treatment zones (first, second, third treatment zones) with different optical powers and characteristics. Each zone is separated by meridians, creating a segmented structure that distributes myopic defocus across multiple regions rather than using a single annular add power region, thereby reducing visual side effects while maintaining effectiveness in slowing myopia progression.
2Reliability
If dual-focus lenses with annular add power regions are used, then myopia progression is slowed, but wearers may inadvertently use the additional focus to view near objects like presbyopes
Solution Approach 1:
Different regions of the lens are assigned different optical properties: the first treatment zone provides myopic defocus for distance vision control, while the second and third treatment zones provide different optical powers for near vision. This local differentiation ensures that young wearers cannot inadvertently use add power for near viewing, preserving natural accommodation while maintaining myopia control effectiveness.
3Adaptability or versatility
If conventional bifocal or multifocal lenses are used for presbyopia, then near and distance vision are corrected, but the design is complex with multiple regions optimized for different visions
Solution Approach 1:
The contact lens design provides multiple functions within a single integrated structure: distance vision correction, near vision correction, and myopia progression control. The lens achieves this through treatment zones positioned at different meridians that collectively provide both distance and near viewing capabilities while maintaining a relatively simple overall lens architecture compared to conventional bifocal or multifocal designs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The lens effectively slows myopia progression while providing clear vision without halos and encourages natural accommodation, improving image quality and comfort for wearers.
Implementation Method 1
Light rays from a distant point source passing through the midpoint of each arc converge towards a point on the first optical axis. For each arc, light rays passing through that arc converge towards a point that is a first distance from the optical axis.
Data Source
AI summary
A contact lens (201) includes an optic zone (202) that is centred on an optical axis (219), and a peripheral zone (204) surrounds the optic zone (202). A cross-sectional slice through the optic zone (202) along a meridian comprises a series of successive arcs (203a-203h) having a radial curvature power profile. The radial curvature power profile increases monotonically with radial distance from the optical axis (219). Light rays from a distant point source passing through the midpoint of each arc converge toward a point (215) on the first optical axis (203a-203h). For each arc (203a-203h), light rays from a distant point source pass through that arc (203a-203h) and converge towards a point (216) that is spaced away from the optical axis by a first distance. Methods of designing and manufacturing such contact lenses (201) are also described.