Multi-ring IOL with Segmented Diffractive Zones for Extended Depth of Focus
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Solution Overview
Problem
Current multifocal intraocular lenses (IOLs) often cause dysphotopsia, such as glare or halos, and compromise intermediate vision due to their bifocality, while existing solutions for extended depth of focus either rely on complex diffractive or refractive principles that are not fully effective.
Innovation Solution
Designing ophthalmic lenses with a limited ring structure featuring a central echelette and a peripheral zone, optimized for optical performance across a range of pupil sizes, which reduces bifocality and minimizes dysphotopsia by distributing light effectively between far and intermediate focuses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional multifocal IOLs are used to provide vision at multiple distances, then vision correction at near and far distances is improved, but dysphotopsia (glare, halos) occurs and intermediate vision is compromised
Solution Approach 1:
The lens is divided into multiple discrete rings (first ring, second ring, third ring) with different optical powers. Each ring segment handles specific focal distances, with the first ring for far vision, second ring for intermediate vision, and third ring for near vision. This segmentation allows independent optimization of each zone to reduce dysphotopsia while maintaining multi-distance vision capability.
Solution Approach 2:
Different regions of the lens are assigned different optical properties: the central first ring has power optimized for far distance, the intermediate second ring has power for intermediate distances, and the peripheral third ring has power for near distances. This local differentiation of optical quality enables tailored vision correction for specific distance ranges while minimizing unwanted optical effects like halos.
2Adaptability or versatility
If bifocal lens design is used to provide near and far vision, then vision at two distances is improved, but intermediate vision is compromised
Solution Approach 1:
The lens is divided into three distinct rings instead of traditional two zones, with the second ring specifically dedicated to intermediate vision. This segmentation creates a dedicated intermediate focal zone that captures light rays intended for intermediate distances, preventing them from being misdirected to near or far focuses, thereby ensuring reliable intermediate vision.
Solution Approach 2:
The invention adds an intermediate focal dimension by introducing a second ring with intermediate optical power between the far-focused first ring and near-focused third ring. This dimensional expansion from bifocal to trifocal architecture provides comprehensive coverage across near, intermediate, and far distance ranges.
3Adaptability or versatility
If complex diffractive or refractive principles are used to achieve extended depth of focus, then depth of focus is extended, but device complexity increases and effectiveness is limited
Solution Approach 1:
The lens uses simple segmented rings with discrete optical powers rather than complex continuous diffractive or refractive surfaces. Each ring is a straightforward optical element with a specific focal power, making the overall structure easier to manufacture and optimize compared to complex gradient-index or diffractive designs.
Solution Approach 2:
The invention achieves extended depth of focus by varying the optical power parameter across different rings rather than using complex spatially varying refractive indices or diffractive patterns. Each ring has a discrete power parameter optimized for its focal range, simplifying the optical design while maintaining effectiveness.
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 proposed lens design enhances image quality across a wide range of foci without dysphotopsia, providing improved vision at multiple distances with reduced halos and improved intermediate vision compared to traditional multifocal IOLs.
Implementation Method 1
a diffractive profile imposed on the anterior refractive profile or the posterior refractive profile, wherein the diffractive profile includes an inner echelette and four or fewer outer echelettes
Implementation Method 2
an anterior face with an anterior refractive profile and a posterior face with a posterior refractive profile
Data Source
AI summary
Systems and methods for providing enhanced image quality across a wide and extended range of foci encompass vision treatment techniques and ophthalmic lenses such as contact lenses and intraocular lenses (IOLs). Exemplary IOL optics can include an aspheric refractive profile imposed on a first or second lens surface, and a diffractive profile imposed on a first or second lens surface. The aspheric refractive profile can focus light toward a far focus. The diffractive profile can include a central zone that distributes a first percentage of light toward a far focus and a second percentage of light toward an intermediate focus. The diffractive profile can also include a peripheral zone, surrounding the central zone, which distributes a third percentage of light toward the far focus and a fourth percentage of light toward the intermediate focus.