Spiral Myopia Control Lens Asymmetry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional myopia control lenses face challenges in maintaining effective myopia control across varying pupil dilation conditions and can cause unwanted visual side effects due to the alternating concentric rings design, which affects the focus of light on the retina and the eye's accommodation ability.
Innovation Solution
The design features a contact lens with a myopia control region in a spiral shape that focuses light to focal points offset from the optical axis, maintaining a consistent ratio of myopic defocus to distance focus across different pupil diameters, reducing variations in myopic defocus and distance focus, and minimizing the risk of reduced accommodation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If concentric rings with alternating lens powers are used, then myopia control is achieved through myopic defocus, but the amount of myopic defocus varies as the pupil dilates and constricts, impairing effectiveness
Solution Approach 1:
The patent replaces the symmetric concentric ring pattern with an asymmetric spiral pattern. The spiral myopia control region does not exhibit radial symmetry, causing light to focus at multiple offset focal points rather than forming concentric rings. This asymmetric design ensures that the ratio of myopic defocus to distance focus remains substantially constant across different pupil diameters, as the spiral geometry distributes optical power differently compared to the conventional symmetric alternating ring design.
2Reliability
If annular myopic defocus regions are used, then myopia progression is slowed, but unwanted visual side effects such as halos and reduced accommodation occur
Solution Approach 1:
The asymmetric spiral pattern eliminates the formation of defocused annular rings at the retina. Because the spiral geometry does not produce concentric circular focal patterns, light does not form the characteristic halos surrounding images that occur with annular defocus regions. Instead, the offset focal points are distributed in a spiral pattern that does not create these harmful visual artifacts.
Solution Approach 2:
Rather than creating myopic defocus through annular regions that focus light in front of the retina (which causes halos), the patent inverts the approach by using a spiral pattern that focuses light at offset points without forming annular defocus regions. This reverses the optical mechanism from creating harmful annular patterns to creating distributed offset focal points that achieve myopia control without the side effects.
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 provides stable and effective myopia control in varying lighting conditions while minimizing the risk of accommodation reduction and unwanted visual side effects, such as halos, by maintaining a consistent ratio of myopic defocus to distance focus across the lens surface.
Implementation Method 1
The myopia control region comprises a spiral shape and focusses light to a plurality of focal points that are offset from the first optical axis
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An ophthalmic lens for use in preventing or slowing the development or progression of myopia. The lens has a first optical axis. A first surface of the lens is shaped to form a first surface power map. A second surface of the lens is shaped to form a second surface power map. The first and second surface power maps together form a lens power map. One of the first surface power map, the second surface power map, and the lens power map comprises: a base region and a myopia control region. The base region has a base power which focusses light to a focal point that is on the first optical axis. The myopia control region comprises a spiral shape and focusses light to a plurality of focal points that are offset from the first optical axis. Also a method of manufacturing such an ophthalmic lens.