Tilted Annular Contact Lens Optics for Halo-Reduced Myopia Control
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Solution Overview
Problem
Conventional contact lenses for myopia correction, such as dual-focus lenses, can cause unwanted visual side effects like halos around images and disrupt natural accommodation due to annular add power regions focusing light in front of the retina, which is undesirable for young subjects.
Innovation Solution
A contact lens design featuring an optic zone with a central portion and a first annular portion providing radial curvature add power, where one surface has a centre of curvature on the optical axis and the other is tilted relative to the axis, focusing light to distinct focal surfaces without forming on-axis images in front of the retina.
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 visual side effects such as halos and rings occur
Solution Approach 1:
The patent applies asymmetry by tilting the annular add power region relative to the optical axis, creating an asymmetric optical design. This tilt prevents the formation of symmetric halos and rings by displacing the defocused light patterns, thereby reducing visual side effects while maintaining the myopia control function
Solution Approach 2:
The patent implements local quality by providing different optical properties in different regions of the lens. The central region provides distance correction while the tilted annular region provides localized myopic defocus. This spatial differentiation allows each region to optimize its specific function without interfering with the other
2Ease of operation
If annular add power regions are used to provide additional focus, then near vision can be improved, but natural accommodation is suppressed
Solution Approach 1:
The patent applies partial action by providing myopic defocus only in the annular region while leaving the central region for distance vision. This partial provision of near vision support allows the eye to maintain natural accommodation for true near tasks while receiving defocus control for intermediate distances, preserving adaptive function
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 design reduces progression of myopia while minimizing halos and allowing natural accommodation, providing clear vision without the need for unnatural eye focusing, suitable for myopic individuals.
Implementation Method 1
A contact lens design featuring an optic zone with a central portion and a first annular portion providing radial curvature add power, where one surface has a centre of curvature on the optical axis and the other surface is tilted relative to the central portion, eliminating the formation of on-axis images in front of the retina
Data Source
AI summary
A contact lens (2001) and methods of manufacturing such a lens (2001) are described. The contact lens (2001) comprises an optic zone (202). The optic zone (202) comprises a central portion having a centre of curvature that is on an optical axis (219), and a first annular portion (203) extending radially outwards from the central portion (205). The first annular portion (203) provides a curvature add power. One of an anterior surface and a posterior surface of the first annular portion (203) has a centre of curvature that is on the optical axis (219). The other of the anterior surface and the posterior surface of the first annular portion (203) has a centre of curvature that is separated by a first distance from the optical axis (219).