Subsurface Optical Structures for Low-Energy Refractive Index Control
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Solution Overview
Problem
Existing treatments for optical aberrations such as astigmatism, myopia, hyperopia, spherical aberrations, coma, and trefoil are limited in efficiency and can cause damage to the eye due to high laser energy requirements for refractive index changes.
Innovation Solution
The use of femtosecond laser pulses to create subsurface optical structures with controlled refractive index variations in ophthalmic lenses, employing an enhanced phase-wrapped phase distribution to minimize laser energy and reduce damage, while providing effective optical corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high laser energy is used to create refractive index changes in the lens material, then optical corrections can be achieved, but material damage is induced
Solution Approach 1:
The patent divides the optical structure into multiple discrete zones with different refractive index values (first limit refractive index and second limit refractive index). Each zone is formed by targeted laser pulses that create distinct refractive index modifications without excessive energy accumulation, thereby achieving precise optical correction while minimizing material damage.
Solution Approach 2:
The patent applies different refractive index values to different spatial locations within the lens material. By creating zones with specific refractive index characteristics (first limit vs. second limit) in different sections of the optical structure, the patent achieves localized optical properties that correct aberrations while controlling laser energy deposition to prevent damage.
2Manufacturing precision
If conventional phase scaling approach is used to form subsurface optical structure, then refractive index distribution can be achieved, but more laser pulses and higher laser energy are required
Solution Approach 1:
The patent employs an enhanced phase-wrapped phase distribution that optimizes the refractive index parameter distribution within the optical structure. By using discrete refractive index values (first limit and second limit) rather than continuous scaling, the patent achieves the desired optical phase correction with fewer laser pulses and reduced total laser energy input.
Solution Approach 2:
The patent creates zones with refractive indexes equal to the first limit refractive index over specific sections where the inner and outer perimeters are separated by at least 0.050 mm. This partial action approach, where only specific zones receive maximum laser treatment, reduces the total number of pulses and energy required compared to treating the entire optical structure uniformly.
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
Achieves improved optical corrections with reduced laser energy, minimizing material damage and requiring fewer laser pulses, thus enhancing diffraction efficiency and modulation transfer function.
Implementation Method 1
subsurface refractive index variations are formed via focusing femtosecond duration laser pulses onto a targeted sequence of subsurface volumes of an ophthalmic lens
Data Source
AI summary
Ophthalmic lenses and related methods employ subsurface optical structures with enhanced refractive index distributions. An ophthalmic lens includes a lens body and a subsurface optical structure within the lens body. Sub-volumes of the optical structure have refractive indexes that vary spatially between a first limit refractive index for the optical structure and a second limit refractive index for the optical structure. The refractive indexes are equal to the first limit refractive index for the optical structure over a first section of the optical structure. The refractive indexes are equal to the second limit refractive index for the optical structure over a second section of the optical structure.