Aspherical Soft Contact Lens Design for Spherical Aberration Control

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Solution Overview

Problem

Existing soft contact lenses fail to effectively address spherical aberration, leading to diminished visual acuity due to uncontrolled combinations of SPHA between the lens and the cornea, which are not systematically designed to consider variations in ocular aberration, manufacturing errors, and accommodative ability.

Innovation Solution

Designing soft contact lenses with tailored levels of spherical aberration to compensate for population-average ocular spherical aberration profiles and manufacturing variations, incorporating specific SPHA profiles across different spherical powers to optimize visual acuity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If spherical surfaces are used in contact lenses to correct myopia or hyperopia, then refractive error is corrected, but spherical aberration occurs causing image blurring and reduced visual acuity

Engineering Contradiction:

Improverefractive correction effectivenessVSAvoidspherical aberration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies aspheric surfaces instead of spherical surfaces in contact lens design. The aspheric front surface has a varying curvature radius from the optical axis to the periphery, creating an asymmetric shape that specifically corrects spherical aberration while maintaining refractive correction effectiveness. This asymmetric design allows different zones of the lens to focus light at the same focal point, eliminating the blurring effect of spherical aberration.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent changes the curvature parameter of the lens surface from constant (spherical) to variable (aspheric). By varying the curvature radius as a function of radial distance from the optical axis, the lens can simultaneously achieve refractive correction and spherical aberration correction. The curvature parameter is specifically designed to compensate for the eye's own spherical aberration characteristics.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If different spherical aberration levels are incorporated for different spherical powers, then visual acuity is improved, but lens design complexity increases

Engineering Contradiction:

Improvevisual acuityVSAvoidlens design

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a systematic parameter change approach where the aspheric coefficient varies according to the spherical power of the lens. Rather than designing completely different lens structures for different powers, the invention modifies the aspheric parameters based on the required spherical correction, creating a scalable design family that maintains visual acuity across different prescription strengths.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The aspheric lens design serves multiple functions simultaneously: it provides refractive correction for myopia or hyperopia, corrects spherical aberration, and maintains rotational symmetry for stable positioning. The single aspheric surface design achieves what would otherwise require multiple complex surface modifications, simplifying the overall lens design while improving visual performance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If population-average ocular spherical aberration profile is compensated for, then visual acuity is improved across the wearing population, but manufacturing precision requirements increase

Engineering Contradiction:

Improvevisual acuity across populationVSAvoidspherical aberration profile control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent establishes specific mathematical relationships between the aspheric coefficients and the spherical power of the lens. These parameter relationships are derived from population-average ocular aberration data, allowing the lens design to automatically compensate for typical spherical aberration across different prescription strengths. The parameters are chosen to provide optimal visual acuity for the average population while accounting for natural variations.

Inventive Principle:

Principle #35Parameter changes

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 designed lenses provide improved visual acuity by minimizing image blurring caused by spherical aberration, outperforming spherical comparator lenses across a range of spherical powers.

Implementation Method 1

light rays from an object are focused in front of the retina... light rays from an object refracted from different radial locations of the lens refocus at different locations or foci along the optical axis

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS12498589B2Aspherical lens design with power dependent spherical aberration

Publication Date: 2025.12.16 JOHNSON & JOHNSON VISION CARE INC

AI summary

Described herein are soft contact lens sets and methods of designing soft contact lens sets based on incorporating different levels of spherical aberration into the lens design depending on the target spherical power. The different levels of spherical aberration are equal to or less than zero D/mm2, and account for clinically measured population-average ocular spherical aberration, manufacturing variations and generalized accommodative ability.