Diffractive Intraocular Lens Zoning for Extended Depth of Focus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ophthalmic lenses, such as multifocal lenses, struggle to provide an extended range of vision (ERV) and efficiently distribute light across near, intermediate, and far distances while minimizing dysphotopsia effects like glare and halo.
Innovation Solution
Diffractive intraocular lenses (IOLs) with a central zone operating in higher diffractive orders and peripheral zones in lower orders, distributing light across multiple focal lengths to achieve an extended depth of focus, incorporating a central, peripheral, and optional intermediate zones to enhance light efficiency and correct chromatic aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional multifocal lenses are used, then multiple focal points are provided, but light distribution efficiency is poor and dysphotopsia effects occur
Solution Approach 1:
The lens is divided into multiple diffractive zones (first zone, second zone, third zone) with progressively increasing outer diameters and different diffractive orders. Each zone segments the light distribution function, with the first zone providing near vision, the second zone providing intermediate vision, and the third zone providing distance vision, thereby improving overall light distribution efficiency across the extended range of vision.
Solution Approach 2:
Each diffractive zone is assigned different local optical properties: the first zone has a first diffractive order optimized for near vision, the second zone has a second diffractive order for intermediate vision, and the third zone has a third diffractive order for distance vision. This local differentiation of optical characteristics enables efficient light distribution to multiple focal points while reducing dysphotopsia effects.
2Adaptability or versatility
If diffractive zones with increasing outer diameters are used, then extended depth of focus is achieved, but lens complexity increases
Solution Approach 1:
The diffractive zones are arranged in a nested configuration where the first zone is centered, the second zone surrounds the first zone with a larger outer diameter, and the third zone surrounds the second zone with the largest outer diameter. This nested structure achieves extended depth of focus through concentric rings of different diffractive orders while maintaining a compact, integrated lens design that reduces manufacturing complexity.
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 lenses provide improved vision across a range of distances with reduced light loss and dysphotopsia, achieving better distance, intermediate, and near image quality compared to traditional multifocal lenses.
Implementation Method 1
A diffractive profile is imposed on one of the surfaces and configured to cause a distribution of non-negligible amounts of light among the depth of focus
Data Source
AI summary
Apparatuses, systems and methods for providing improved ophthalmic lenses, particularly intraocular lenses (IOLs). Exemplary diffractive intraocular implants (IOLs) can include a diffractive profile having multiple diffractive zones. The diffractive zones can include a central zone that includes one or more echelettes and a peripheral zone beyond the central zone having one or more peripheral echelettes. The central diffractive zone can work in a higher diffractive order than a remainder of the diffractive profile. The combination of the central and peripheral zones and an optional intermediate zone provides a longer depth of focus than a diffractive profile defined just by a peripheral and/or optional intermediate zone.