for essilor progressive lenses what cross height amount or b
When selecting Essilor progressive lenses, particularly for short corridor designs, it's crucial to consider the appropriate measurements for cross height and B size. For optimal fitting, a general guideline suggests adding 2 mm to 4 mm to the minimum fitting height of the lenses. This adjustment helps ensure that the wearer experiences better vision across different zones of the lenses.
The fitting height typically ranges from 18 mm to 22 mm, with the corridor length for these lenses usually falling between 14 mm to 18 mm. This corridor length is critical because it affects how the wearer transitions between various visual zones such as distance, intermediate, and near. Therefore, ensuring that the frame allows sufficient space between the lower rim and the bottom of the pupil is essential for the efficacy of short corridor lenses.
Further detailed insights can be found in various resources, including the fitting and dispensing guide provided by Essilor that discusses the design variations in modern progressive addition lenses (PALs) and their implications on fitting heights. Another informative source is the 20/20 Magazine's article on coping with corridors, highlighting the importance of accurate measurements.
For more comprehensive information, you can refer to the following links:
- Coping with Corridors - 20/20 Magazine
- Essilor Ideal® Lens Cutout Chart (PDF)
- Understanding Today's Progressives
- Fitting & Dispensing Guide (PDF)
By adhering to these guidelines and utilizing the mentioned resources, one can make informed decisions regarding the specifications needed for short corridor progressive lenses.
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