Multifocal Ophthalmic Lens Surface Profile for Extended Depth of Focus

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Solution Overview

Problem

Existing multifocal lenses often result in visual irregularities due to the coexistence of distinctive defocused and sharply focused images, particularly as the human eye ages and its ability to adapt to different distances declines.

Innovation Solution

An ophthalmic lens with a surface profile featuring a base curvature and multiple zones that include adjustments such as spherical aberrations, longitudinal chromatic aberrations, and phase shifts to extend the depth-of-focus, providing continuous vision by smoothly transitioning between near, intermediate, and distance corrections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional multifocal lenses are used to provide correction at different focal lengths, then vision at multiple distances is improved, but visual irregularities occur due to coexistence of defocused and sharply focused images

Engineering Contradiction:

Improvevision at multiple distancesVSAvoidvisual irregularities

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The lens is divided into multiple zones along the optical axis, with each zone providing a specific focal length correction. The surface profile includes a first zone for distance correction, a second zone for intermediate correction, and a third zone for near correction, allowing segmented optical functions to coexist without visual irregularities

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the lens are assigned different optical properties through the surface profile design. Each zone has customized optical parameters (curvature, thickness, refractive index) optimized for its specific focal length requirement, creating locally optimized optical quality throughout the lens structure

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the human eye ages and its ability to adapt to different distances declines, then presbyopia develops requiring multifocal lenses, but the transition between focal lengths becomes more difficult

Engineering Contradiction:

Improveaccommodation abilityVSAvoidtransition between focal lengths

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The surface profile creates continuous light energy distribution across multiple focal lengths without abrupt transitions. The optical zones are designed with smooth gradients and overlapping focal ranges, enabling continuous vision from near to distance without sudden jumps or adaptation difficulties

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The lens provides dynamic focal length adjustment capability through its multi-zone design, allowing the eye to naturally transition between focal planes as needed. The surface profile creates a dynamic optical field that adapts to varying viewing distances without requiring active accommodation effort

Inventive Principle:

Principle #15Dynamics

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 provides a broad range of continuous vision by minimizing visual disturbances through improved distance refraction targeting and smoothing transitions between focal points, enhancing overall visual clarity.

Implementation Method 1

at least one of the first surface and the second surface includes a surface profile having a base curvature and a plurality of zones. The base curvature corresponds to a base optical power. The plurality of zones is adapted to produce a plurality of curves corresponding to light energy distribution along the optical axis.

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

The plurality of adjustments may include at least one spherical aberration.

Methodology Applied

Scientific EffectSpherical aberration:

Implementation Method 3

The plurality of adjustments may include at least one longitudinal chromatic aberration.

Methodology Applied

Scientific EffectLongitudinal chromatic aberration:

Implementation Method 4

The plurality of adjustments may include at least one phase shift change.

Methodology Applied

Scientific EffectPhase shift:

Data Source

PatentUS20250347931A1Multifocal ophthalmic lens with extended depth-of-focus

Publication Date: 2025.11.13 ALCON INC

AI summary

An ophthalmic lens includes an optic having a first surface and a second surface disposed about an optical axis. At least one of the first surface and the second surface includes a surface profile having a base curvature and a plurality of zones. The base curvature corresponds to a base optical power. The plurality of zones is adapted to produce a plurality of curves corresponding to light energy distribution along the optical axis. The surface profile includes a plurality of adjustments providing an extended depth-of-focus, the plurality of adjustments being adapted to extend each one of the plurality of curves towards another of the plurality of curves. The plurality of adjustments may include at least one spherical aberration. The plurality of adjustments may include at least one longitudinal chromatic aberration. The plurality of adjustments may include at least one phase shift change.