Tilted Annular Contact Lens Optics to Minimize Halos

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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 require the eye to accommodate in an undesirable manner, while dual-focus lenses may not effectively prevent myopia progression without these issues.

Innovation Solution

A contact lens design featuring a central region with a base power and an annular region tilted relative to the central region, where the annular region has a higher radial curvature and sagittal power than the central region, providing myopic defocus without forming on-axis images in front of the retina, thus reducing myopia progression and enhancing depth of focus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If annular add power regions are used to slow myopia progression, then myopia control is improved, but visual side effects such as halos around images occur

Engineering Contradiction:

Improvemyopia control effectivenessVSAvoidvisual side effects (halos)

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The annular region is deliberately tilted relative to the optical axis, creating asymmetric optical properties. This tilt causes the annular region to focus light at different locations for different meridians, preventing the formation of a single on-axis image and thereby reducing halo effects while maintaining myopic defocus for myopia control

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

Different regions of the lens are given different optical properties: the central region provides base power for distance vision, while the tilted annular region provides myopic defocus with asymmetric curvature. This local differentiation allows simultaneous achievement of myopia control and reduced visual side effects

Inventive Principle:

Principle #3Local quality

2Reliability

If annular add power regions are used to slow myopia progression, then myopia control is improved, but presbyopes may inadvertently use the lenses for near vision

Engineering Contradiction:

Improvemyopia control effectivenessVSAvoidunintended presbyopic correction

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The tilt of the annular region creates asymmetric optical characteristics that prevent the formation of a clear on-axis image at the near focal plane. This asymmetry ensures that while myopic defocus is provided for myopia control, the lens does not provide usable near vision correction, thereby preventing presbyopic misuse

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

Instead of providing clear near vision through the annular region (which would allow presbyopic use), the design inverts the approach by creating deliberate optical asymmetry that prevents clear imaging at the near focal plane, thereby blocking unintended presbyopic correction

Inventive Principle:

Principle #13The other way round (Inversion)

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 minimizes halos and allows natural accommodation, effectively slowing myopia progression while maintaining clear vision by distributing light focus across a focal line on the retina, providing an extended depth of focus.

Implementation Method 1

The annular region has a greater radial curvature power than the central region, providing a more positive or less negative power to the eye. The add power region(s) are designed to focus incoming parallel light (i.e., light from a distance) within the eye in front of the retina

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

The annular region has an off-axis centre of curvature that is a first distance from the optical axis. The annular region is tilted relative to the central region to prevent the formation of a single on-axis image in front of the retina

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS12631904B2Contact lenses and methods relating thereto

Publication Date: 2026.05.19 COOPERVISION INT LTD

AI summary

A contact lens (201) and methods of manufacturing such a lens are described. The lens (201) includes an optic zone (202). The optic zone (202) comprises a central region (205), the central region (205) having a first optical axis (219), a base radial curvature power, a base radial sagittal power, and a centre of curvature that is on the first optical axis (219). The optic zone (202) comprises an annular region (203), wherein at a point halfway across the width of the annular region (203) the annular region (203) has a radial curvature power of X, wherein X is greater than the base radial curvature power. The annular region (203) has an off-axis centre of curvature that is a first distance from the optical axis (219) such that, at a point halfway across its width, the annular region (203) has a sagittal power of Y, wherein Y is greater than the base radial sagittal power, and wherein Y is less than X.