Apodized Diffractive Intraocular Lens for Distance Vision Energy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional intraocular lenses (IOLs) lack the ability to accommodate power variations for a range of focal distances, requiring patients to choose a specific focal power for near or far vision and relying on eyeglasses for intermediate vision, which limits the eye's natural accommodation.
Innovation Solution
A tri-focal IOL design featuring diffractive profiles on a base refractive surface with non-harmonic periodicities, where the energy distribution shifts towards distance vision under low light conditions and maintains good near and intermediate vision under bright light conditions by apodizing diffractive step heights as a function of radial distance, ensuring a stable transition between focal zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If diffractive profiles are used to provide multiple focal powers, then near and intermediate vision are improved, but distance vision energy is reduced under mesopic conditions
Solution Approach 1:
The patent applies local quality by varying the diffractive step heights as a function of radial distance from the optical axis. The apodization function creates different diffractive properties in different radial zones: central zones maintain higher step heights for near/intermediate vision, while peripheral zones reduce step heights to favor distance vision under mesopic conditions. This radial variation in local diffractive quality resolves the energy distribution contradiction.
Solution Approach 2:
The patent implements dynamics through the apodization function that dynamically adjusts the relative energy distribution to near, intermediate, and distance foci based on pupil size. As the pupil enlarges under mesopic conditions, the effective diffractive profile changes radially, automatically shifting energy distribution to favor distance vision while maintaining near/intermediate vision capability. This dynamic adaptation resolves the energy allocation contradiction.
2Reliability
If diffractive step heights are increased to enhance near and intermediate vision, then near and intermediate focal powers are improved, but unwanted visual effects increase under low light conditions
Solution Approach 1:
The patent reduces unwanted visual effects by applying local quality variation through the apodization function. By reducing diffractive step heights in peripheral zones while maintaining them in central zones, the lens provides reliable near and intermediate vision through the pupil center while minimizing harmful diffraction effects at the pupil periphery under mesopic conditions. This spatially differentiated approach resolves the contradiction between vision quality and harmful effects.
3Ease of manufacture
If monocular IOL with fixed focal power is used, then manufacturing simplicity is maintained, but accommodation for range of focal distances is lost
Solution Approach 1:
The patent applies segmentation by dividing the lens aperture into multiple functional zones with different diffractive step heights. The apodization function creates distinct radial zones that independently contribute to different focal powers (distance, intermediate, near). This segmentation allows a single lens to provide multiple focal capabilities while maintaining a relatively simple monocular structure, resolving the contradiction between manufacturing simplicity and focal versatility.
Solution Approach 2:
The patent implements multi-functionality by designing a single IOL that simultaneously provides distance, intermediate, and near vision capabilities through the apodized diffractive profile. The continuous variation of step heights creates multiple effective focal powers from one lens structure, making the lens universal for all viewing distances while maintaining manufacturing feasibility. This resolves the contradiction between simplicity and versatility.
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
This design minimizes unwanted visual effects by increasing distance vision energy under mesopic conditions, providing a stable transition between near and intermediate vision, and extending the depth of focus for near vision, while maintaining optical clarity across varying pupil sizes.
Implementation Method 1
a diffractive structure formed in one of the surfaces of the base refractive structure including overlapping first and second diffractive patterns over a common aperture for producing second and third optical powers
Implementation Method 2
a base refractive structure having anterior and posterior surfaces that are shaped for producing a first optical power
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
An intraocular lens includes a base refractive structure having anterior and posterior surfaces that are shaped for producing a first optical power and a diffractive structure formed in one of the surfaces of the base refractive structure including overlapping first and second diffractive patterns over a common aperture for producing second and third optical powers. The second optical power is an uneven division of the third optical power. The first and second diffractive patterns have respective step heights that are separately varied as a function of radial distance from the optical axis over the common aperture.