Multifocal Diffractive Lens Echellettes for Vision Correction
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Solution Overview
Problem
Existing multifocal ophthalmic lenses, such as diffractive multifocal intraocular lenses and contact lenses, often cause unwanted light-related visual phenomena like halos and light scatter due to inefficient light energy distribution and sensitivity to wavelength, leading to suboptimal vision quality, especially in presbyopic patients.
Innovation Solution
A multifocal diffractive lens structure with a combination of substantially monofocal echellettes for near, far, and intermediate vision corrections, where the echellettes are designed to diffract at least 90% of transmitted light to their respective orders, reducing light scatter and chromatic aberration, and are arranged to minimize diffraction to non-viewing orders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If diffractive multifocal lenses are used to provide multiple focal distances, then near and far vision correction is improved, but unwanted light-related visual phenomena (halos, light scatter) increase
Solution Approach 1:
The lens is divided into multiple zones with different diffractive orders, where each zone directs light to specific focal points. The lens segments light energy into distinct pathways for near, intermediate, and far vision while minimizing overlap and scatter between zones.
Solution Approach 2:
Different regions of the lens are assigned different optical properties and diffractive characteristics tailored to specific viewing distances. The lens applies localized optimizations for near vision, intermediate vision, and far vision zones to improve overall performance while reducing unwanted light effects in each region.
2Adaptability or versatility
If diffractive multifocal lenses direct light to multiple foci, then presbyopia is mitigated, but dysphotopsia increases
Solution Approach 1:
The design extracts and eliminates diffractive orders that contribute to dysphotopsia while retaining those that provide useful vision correction. By selectively removing harmful diffraction components, the lens reduces dysphotopic symptoms while maintaining presbyopia correction functionality.
Solution Approach 2:
The lens converts potentially harmful light scatter and dysphotopsia-causing diffraction into beneficial focused light delivery. By carefully designing the diffractive structure, light that might otherwise cause dysphotopsia is redirected to form sharp images at the intended focal points for near, intermediate, and far vision.
3Use of energy by moving object
If diffractive lenses are optimized for a specific wavelength, then diffraction efficiency is improved, but vision quality decreases at other wavelengths
Solution Approach 1:
The diffractive lens structure is designed to function effectively across multiple wavelengths of visible light, not just at a single design wavelength. The optical elements are engineered to provide consistent performance for polychromatic light, enabling the lens to maintain high diffraction efficiency and vision quality across the entire visible spectrum.
4Adaptability or versatility
If multifocal diffractive profiles are used to provide multiple optical powers, then presbyopia is corrected, but light energy is scattered to non-viewing foci
Solution Approach 1:
The lens dynamically adapts light distribution based on viewing conditions and pupil size. The diffractive structure adjusts the proportion of light directed to near, intermediate, and far focal points, optimizing light energy utilization while minimizing waste to non-viewing foci under different operational conditions.
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 significantly improves vision quality by reducing light scatter and chromatic aberration, providing better depth perception and intermediate vision correction, while inhibiting dysphotopsia and enhancing overall viewing performance across different pupil sizes.
Implementation Method 1
The first plurality of substantially monofocal echellettes diffracts transmitted light with an efficiency of at least about 90% and the second plurality of substantially monofocal echellettes diffracts transmitted light with an efficiency of at least about 90%
Data Source
AI summary
A multifocal diffractive lens comprises a multifocal diffractive structure coupled to a refractive component. The refractive component comprises at least one curved surface. The multifocal diffractive structure comprises a first plurality of substantially monofocal echellettes having a first optical power for near vision correction and a second plurality of substantially monofocal echellettes for far vision correction. The first plurality of substantially monofocal echellettes combined with the second plurality of substantially monofocal echellettes can provide a multifocal diffractive profile having decreased light scatter, chromatic aberration, and diffraction to non-viewing orders such that dysphotopsia is substantially inhibited. A third plurality of substantially monofocal echellettes having an intermediate optical power can be combined with the first plurality of substantially monofocal echellettes and the second plurality of substantially monofocal echellettes.