Diffractive IOL Echelette Profiles for Extended Focus Without Halos
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Solution Overview
Problem
Current multifocal intraocular lenses (IOLs) often result in undesirable visual effects such as glare or halos due to compromised intermediate vision and limited depth of focus, with existing solutions failing to provide enhanced image quality across a wide range of foci without dysphotopsia.
Innovation Solution
The development of ophthalmic lenses featuring a diffractive profile with echelettes of varying widths in r-squared space, allowing for a more complex light distribution that extends the depth of focus and reduces visual symptoms, incorporating a combination of diffractive and refractive zones to optimize vision at multiple distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multifocal IOLs are used to provide vision at multiple distances, then near and far vision are improved, but intermediate vision is compromised and dysphotopsia occurs
Solution Approach 1:
The diffractive profile is segmented into multiple echelettes with different optical powers, where each echelette targets a specific focal distance (near, intermediate, far). This segmentation allows light to be distributed across multiple foci simultaneously, providing comprehensive vision correction while reducing dysphotopsia through optimized light distribution.
Solution Approach 2:
Different regions of the lens aperture are assigned different diffractive properties through the echelette structure. Each echelette has locally optimized characteristics (width, step height, position) to direct light to specific focal points, enabling spatially varying optical functionality that addresses both vision range and dysphotopsia reduction.
2Ease of manufacture
If diffractive profiles with uniform echelettes are used, then manufacturing is simplified, but depth of focus is limited and visual symptoms increase
Solution Approach 1:
The echelettes are designed with asymmetric and varied dimensions, where each echelette has different width, step height, and radial position. This asymmetry optimizes light distribution across multiple foci and reduces visual symptoms, while the systematic variation pattern maintains manufacturability through repeatable fabrication processes.
Solution Approach 2:
The optical parameters of the echelettes (width, height, position, step depth) are systematically varied to achieve different diffractive powers and focal distributions. This parameter optimization extends depth of focus and reduces dysphotopsia while maintaining compatibility with standard lens manufacturing techniques.
3Measurement precision
If conventional monofocal IOLs are used, then image quality at one distance is optimized, but vision at other distances requires spectacles
Solution Approach 1:
The diffractive lens profile integrates multiple optical functions within a single lens structure. The echelettes simultaneously provide refractive correction for distance vision and diffractive correction for near and intermediate vision, making the lens universal for multiple viewing distances and eliminating the need for additional corrective devices.
Solution Approach 2:
The design merges refractive and diffractive optical principles into a unified lens structure. The echelettes combine both refractive power (from the lens curvature) and diffractive power (from the stepped profile), creating a hybrid optical system that delivers multiple foci from a single integrated element.
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 solution enhances image quality by providing improved vision across an extended range of foci, reducing dysphotopsia and enhancing intermediate vision, while maintaining clear distance and near vision, thus addressing the limitations of existing multifocal IOLs.
Implementation Method 1
Multifocal IOLs may, for example, rely on a diffractive optical surface to direct portions of the light energy toward differing focal distances
Implementation Method 2
Diffractive monofocal and multifocal lenses 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 improved extended depth of focus lenses. Exemplary ophthalmic lenses can include an optic including a diffractive profile including at least one set of echelettes, each echelette of the set having a different width in r-squared space than any other echelette of the set and the at least one set of echelettes repeating at least once upon the optic.