Multi-Zone Diffractive Lenses for Intermediate Vision and Halo Reduction
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Solution Overview
Problem
Current multifocal ophthalmic lenses, such as diffractive and extended depth of focus lenses, often cause undesirable visual effects like glare or halos, and compromise intermediate vision, despite providing adequate near and far vision.
Innovation Solution
The lenses feature a diffractive profile with echelettes that include optical zones with a gradual change in slope, featuring a change in sign of the slope, and a central zone with a first refractive shape and a peripheral zone with a greater curvature, allowing for improved light distribution and reduced chromatic aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multifocal ophthalmic lenses are used to provide vision at multiple distances, then near and far vision are improved, but intermediate vision is compromised and visual symptoms like glare and halos occur
Solution Approach 1:
The patent applies local quality by creating different optical zones within the lens with distinct functions. The lens includes a central optical zone for distance vision, an intermediate annular zone for intermediate vision, and a peripheral annular zone for near vision. Each zone has optimized optical properties to minimize visual symptoms while providing clear vision at its designated distance range.
Solution Approach 2:
The patent segments the lens into multiple functional zones with different optical powers and characteristics. By dividing the lens into central and peripheral annular zones with specific diffractive profiles and refractive indices, it provides clear vision at multiple distances while reducing the overlap that causes glare and halos.
2Adaptability or versatility
If diffractive lenses are used to extend depth of focus, then continuous vision from far to near is achieved, but chromatic aberration increases
Solution Approach 1:
The patent uses composite materials by combining lens zones with different refractive indices. The central optical zone has a first refractive index optimized for distance vision with minimal chromatic aberration, while the peripheral annular zone has a second refractive index optimized for near vision. This composite structure extends depth of focus while managing chromatic aberration through material differentiation.
Solution Approach 2:
The patent applies parameter changes by varying the refractive index across different lens zones. The central zone uses a refractive index optimized for distance vision, while the peripheral zone uses a different refractive index for near vision. This parameter variation allows extended depth of focus while controlling chromatic aberration through zone-specific optimization.
3Measurement precision
If monofocal IOLs are used to provide clear distance vision, then distance vision is improved, but near and intermediate vision require spectacles
Solution Approach 1:
The patent applies universality by designing a single lens that performs multiple functions: providing clear vision at distance, intermediate, and near ranges. The multi-zone structure with different optical powers allows the lens to serve as a replacement for both monofocal IOLs and reading glasses, eliminating the need for spectacles across all distance ranges.
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 solution enhances the range of vision by providing clear vision at various distances, including intermediate distances, while minimizing visual symptoms like glare and halos, and optimizing chromatic correction for improved visual performance.
Implementation Method 1
diffractive optical surfaces have created extended depth of focus and/or extended range of vision lenses which allow for continuous vision from far to near
Implementation Method 2
Current state of the art diffractive monofocal, extended depth of focus (EDOF), and multifocal lenses, and in general, non-accommodative lenses providing a full range of vision, can make use of a material having a given refractive index and a surface curvature which provide a refractive power
Data Source
AI summary
Apparatuses, systems and methods for providing improved ophthalmic lenses, particularly intraocular lenses (IOLs), include features for providing a range of vision. Chromatic aberrations may be reduced at near, distance, and intermediate vision.