logging in or signing up Progressive addition lenses optometrist.pal Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 874 Category: Education License: All Rights Reserved Like it (4) Dislike it (0) Added: August 07, 2010 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... By: soulsun (16 month(s) ago) very good. thanks for share Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Progressive Addition Lenses -The future of Presbyopes : Progressive Addition Lenses -The future of Presbyopes Pallavi A. Agarkar Progressive Addition Lenses : Progressive Addition Lenses History: The concept of a Progressive Addition Lens (PAL) has been around since 1907. The first PAL was known as an Omnifocal Lens. They are also called as ‘Invisible Bifocals’ or ‘No-line Bifocals’. Progressive Addition Lenses : Progressive Addition Lenses A lens designed for presbyopes with power gradually increasing from the Distance zone through a progression in the Near zone. Optics Of PAL’s : Optics Of PAL’s Power Progression : Power Progression Zones of PAL’s: : Zones of PAL’s: A typical, general-purpose progressive lens will have three distinct zones of vision: Distance Intermediate Near Zones of PAL : Zones of PAL Slide 8: Distance: A designated zone located in the upper portion of the lens, which provides the necessary distance correction. Slide 9: Intermediate: A ‘corridor’ in the central portion of the lens connects the distance and the near zones, which increases progressively in plus power from the distance to near. Slide 10: Near: A designated zone in the lower portion of the lens, which provides the required near addition (or add power). Slide 11: These three zones of vision blend together seamlessly, providing the wearer with a continuous depth of field from near to far. Field of View with PAL’s : Field of View with PAL’s Advantages : Advantages Complete Range of Working Distances Advantages : Advantages Poor Head Position Natural head Position Advantages : Advantages Comfortable Near & Intermediate work Advantages : Advantages No Image Jump Advantages : Advantages Improved Appearance Limitations : Limitations Peripheral Aberrations Expensive Optical Design : Optical Design (1) DRC: Power for distance Rx is verified in the arc above fitting cross.(2) PRF: Prism is verified at the Prism Reference Point (optical center of lens blank).(3) NRC: Full power for near is verified in the bottom of circle.(4) Seg Height is measured from fitting cross to deepest point of the lens/frame. Optical Design : Optical Design Engravings located on temporal and nasal side: (5) Micro Etching: Top engravings provide axis reference. (6) Addition: Lower temporal provides add power. (7) Logo: Lower nasal provides brand logo. Design : Design Hard Design Wide Distance & Near zones. Narrow Intermediate Zone. Shorter progression. Increase in unwanted astigmatism. Soft Design Narrower Distance & Near zones. Wider Intermediate zones. Longer progression. Gradual increase in unwanted astigmatism. Hard and Soft design : Hard and Soft design Symmetrical PAL’s : Symmetrical PAL’s The right and left lenses are identical. Nasal decentraton of the near zones is achieved by lens rotation in equal and opposite amounts. But a vertical prism imbalance is induced between two eyes which results in longer adaptation. Asymmetrical PAL’s : Asymmetrical PAL’s These lenses have a nasal offset of the near addition. Hence the need for lens rotation is minimized and there is no introduction of vertical prism imbalance. Adaptation is better. Indications : Indications Relative Distance, Intermediate & Near work Indications : Indications First-timers having trouble with short-range vision People with single-vision reading glasses who have trouble seeing a bit farther Contraindications : Contraindications Lot of Table Work eg: Architect Change in Direction of gaze eg: Librarians Contraindications : Contraindications Head & Body Movement eg: Sportsman Fitting Requirements : Fitting Requirements Pupillary distance and height of the gaze. Vertex distance. Slide 30: Pantoscopic tilt. Working or reading distance Fitting Requirements Points to remember : Points to remember Performing an accurate sphero-cylinderical refraction. Adjusting the frame properly. Taking accurate monocular PD measurements. Marking and checking the monocular PD’s and fitting heights. Providing proper instructions on use. Motivating the wearer to adapt to the new type of vision. Slide 32: Thank you ! You do not have the permission to view this presentation. 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Progressive addition lenses optometrist.pal Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 874 Category: Education License: All Rights Reserved Like it (4) Dislike it (0) Added: August 07, 2010 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... By: soulsun (16 month(s) ago) very good. thanks for share Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Progressive Addition Lenses -The future of Presbyopes : Progressive Addition Lenses -The future of Presbyopes Pallavi A. Agarkar Progressive Addition Lenses : Progressive Addition Lenses History: The concept of a Progressive Addition Lens (PAL) has been around since 1907. The first PAL was known as an Omnifocal Lens. They are also called as ‘Invisible Bifocals’ or ‘No-line Bifocals’. Progressive Addition Lenses : Progressive Addition Lenses A lens designed for presbyopes with power gradually increasing from the Distance zone through a progression in the Near zone. Optics Of PAL’s : Optics Of PAL’s Power Progression : Power Progression Zones of PAL’s: : Zones of PAL’s: A typical, general-purpose progressive lens will have three distinct zones of vision: Distance Intermediate Near Zones of PAL : Zones of PAL Slide 8: Distance: A designated zone located in the upper portion of the lens, which provides the necessary distance correction. Slide 9: Intermediate: A ‘corridor’ in the central portion of the lens connects the distance and the near zones, which increases progressively in plus power from the distance to near. Slide 10: Near: A designated zone in the lower portion of the lens, which provides the required near addition (or add power). Slide 11: These three zones of vision blend together seamlessly, providing the wearer with a continuous depth of field from near to far. Field of View with PAL’s : Field of View with PAL’s Advantages : Advantages Complete Range of Working Distances Advantages : Advantages Poor Head Position Natural head Position Advantages : Advantages Comfortable Near & Intermediate work Advantages : Advantages No Image Jump Advantages : Advantages Improved Appearance Limitations : Limitations Peripheral Aberrations Expensive Optical Design : Optical Design (1) DRC: Power for distance Rx is verified in the arc above fitting cross.(2) PRF: Prism is verified at the Prism Reference Point (optical center of lens blank).(3) NRC: Full power for near is verified in the bottom of circle.(4) Seg Height is measured from fitting cross to deepest point of the lens/frame. Optical Design : Optical Design Engravings located on temporal and nasal side: (5) Micro Etching: Top engravings provide axis reference. (6) Addition: Lower temporal provides add power. (7) Logo: Lower nasal provides brand logo. Design : Design Hard Design Wide Distance & Near zones. Narrow Intermediate Zone. Shorter progression. Increase in unwanted astigmatism. Soft Design Narrower Distance & Near zones. Wider Intermediate zones. Longer progression. Gradual increase in unwanted astigmatism. Hard and Soft design : Hard and Soft design Symmetrical PAL’s : Symmetrical PAL’s The right and left lenses are identical. Nasal decentraton of the near zones is achieved by lens rotation in equal and opposite amounts. But a vertical prism imbalance is induced between two eyes which results in longer adaptation. Asymmetrical PAL’s : Asymmetrical PAL’s These lenses have a nasal offset of the near addition. Hence the need for lens rotation is minimized and there is no introduction of vertical prism imbalance. Adaptation is better. Indications : Indications Relative Distance, Intermediate & Near work Indications : Indications First-timers having trouble with short-range vision People with single-vision reading glasses who have trouble seeing a bit farther Contraindications : Contraindications Lot of Table Work eg: Architect Change in Direction of gaze eg: Librarians Contraindications : Contraindications Head & Body Movement eg: Sportsman Fitting Requirements : Fitting Requirements Pupillary distance and height of the gaze. Vertex distance. Slide 30: Pantoscopic tilt. Working or reading distance Fitting Requirements Points to remember : Points to remember Performing an accurate sphero-cylinderical refraction. Adjusting the frame properly. Taking accurate monocular PD measurements. Marking and checking the monocular PD’s and fitting heights. Providing proper instructions on use. Motivating the wearer to adapt to the new type of vision. Slide 32: Thank you !