Continuous Aspheric Intraocular Lens for Reduced Halos and Glare
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Solution Overview
Problem
Multifocal intraocular lenses (IOLs) cause visual artifacts such as glare, halos, and decreased contrast sensitivity due to abrupt changes in optical power between zones, limiting their performance in low-light conditions and reducing depth of focus to near and far vision.
Innovation Solution
Designing IOLs with a continuous aspheric surface defined by a single aspheric equation that approximates multiple optical zones without abrupt transitions, using high-order terms to smooth curvature changes and reduce dysphotopsia effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multifocal intraocular lenses with multiple optical zones are used, then vision at different viewing distances is improved, but visual artifacts such as glare and halos increase
Solution Approach 1:
The patent applies aspheric surfaces with continuous curvature variations to replace the discrete zonal structures of traditional multifocal lenses. The aspheric profile creates a smooth power progression from center to periphery, eliminating abrupt curvature changes at zone boundaries that cause visual artifacts. This maintains the multifocal capability while removing the harmful dysphotopsia effects through continuous geometric transition.
Solution Approach 2:
The patent changes the optical power parameter from discrete step-wise values in traditional multifocal lenses to a continuous gradient distribution. By varying the curvature radius continuously across the lens surface according to an aspheric equation, the design achieves multiple focal points without abrupt transitions. This parameter transformation eliminates the sharp boundaries that generate glare and halos while preserving extended depth of focus.
2Adaptability or versatility
If abrupt optical power transitions between zones are implemented, then multiple focal distances are achieved, but contrast sensitivity decreases
Solution Approach 1:
The patent ensures continuous optical power distribution across the entire lens surface through aspheric design. Instead of discrete optical zones with abrupt boundaries, the aspheric surface provides uninterrupted power progression, eliminating the sharp transitions that scatter light and reduce contrast. This continuous action maintains image quality while achieving multifocal functionality.
3Duration of action of moving object
If multiple optical zones with different curvatures are used, then depth of focus is extended, but visual artifacts increase
Solution Approach 1:
The patent uses aspheric surfaces with continuously varying curvature to extend depth of focus without creating discrete zone boundaries. The smooth curvature transition from central to peripheral regions provides multiple focal points while eliminating the abrupt changes that generate visual artifacts. This geometric approach maintains optical quality throughout the extended depth of focus range.
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 continuous aspheric IOLs provide improved optical performance in low-light conditions, reducing visual artifacts and increasing depth of focus to include intermediate distances, similar to monofocal lenses.
Implementation Method 1
IOLs with a continuous refractive aspheric surface that results in a radial power progression
Data Source
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AI summary
Apparatuses, systems and methods for providing improved intraocular lenses (IOLs), include features for reducing side effects, such as halos, glare and best focus shifts, in multifocal refractive lenses and extended depth of focus lenses. Exemplary ophthalmic lenses can include a continuous, power progressive aspheric surface based on two or more merged optical zones, the aspheric surface being defined by a single aspheric equation. Continuous power progressive intraocular lenses can mitigate optical side effects that typically result from abrupt optical steps. Aspheric power progressive and aspheric extended depth of focus lenses can be combined with diffractive lens profiles to further enhance visual performance while minimizing dysphotopsia effects. The combination can provide an increased depth of focus that is greater than an individual depth of focus of either the refractive profile or the diffractive profile.