Progressive Lens Intermediate Zone Alignment
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Solution Overview
Problem
Progressive lenses often require users to tilt their heads to focus on objects at intermediate distances between the near and far focal zones, as the intermediate focal zones on each eye may not be aligned, leading to one eye being out of focus.
Innovation Solution
Designing lenses with intermediate focal zones that are coordinated to have the same height on both eyes, ensuring that focal zones for specific distances between the near and far zones are aligned, allowing for clear vision without head tilting by matching the location of focal zones on the lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If progressive lenses are designed with intermediate focal zones, then vision at intermediate distances can be achieved, but the intermediate focal zones on each eye may not be aligned requiring head tilting
Solution Approach 1:
The patent applies asymmetry by intentionally designing the progressive lenses for the left and right eyes with different optical characteristics. Specifically, the lenses have asymmetric intermediate focal zones positioned at different vertical locations to compensate for the natural asymmetry in human eye positioning and orientation, thereby aligning the effective focal points without requiring head tilting.
Solution Approach 2:
The patent implements local quality by creating non-uniform optical power distributions within each lens. Each progressive lens has locally optimized focal zones at specific vertical positions tailored to the individual eye's requirements, with the left and right lenses having different local focal zone positions to achieve proper alignment when viewed from the user's perspective.
2Ease of manufacture
If traditional progressive lenses are manufactured, then production processes are simplified, but intermediate focal zones are not aligned between left and right lenses
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-positioning the intermediate focal zones during the lens design and manufacturing planning stage. The optical prescription includes predetermined vertical positions for intermediate focal zones on each lens, allowing manufacturers to produce the lenses using standard processes while ensuring the focal zones will be properly aligned when the lenses are worn.
Solution Approach 2:
The patent implements feedback by using the determined optical prescription as a guide for manufacturing. The prescription data, which includes the specific vertical positions of intermediate focal zones for each eye, feeds into the lens manufacturing process to ensure precise placement of focal zones, and the resulting lenses are then verified to provide proper alignment.
Data Source
AI summary
A method comprising: performing eye exam to a subject having a first and second eye; determining a prescription for the first and second eyes, the prescription describing focal power for each of the first eye and the second eye for at least three distances; and providing the prescription to a machine that produces progressive glasses that comprise a first and second lenses, wherein the first and second lenses each having at least three focal portions associated with the at least three distances that are located in a same height in the glasses thereby enabling clear vision for the subject in the first eye and the second eye with respect to the at least three distances.