3. RANGE OF CLEAR VISION Single vision Bifocal Progressive 0.33 0.50 1.00 2.00 5.00 NEAR INTERMEDIATE DISTANCE NEAR INTERMEDIATE DISTANCE NEAR INTERMEDIATE DISTANCE
8. Binocular Vision Binocular vision: As the patient’s gaze is lowered for near objects, the eyes converge to maintain a single binocular image. The progressive lenses should ensure that this is maintained for different object distances from the eyes, as illustrated by the lines.
9. Peripheral (Extra-Foveal) Vision Peripheral vision: The PAL design should ensure that *objects in the periphery of the visual field are easily fused. **The distribution of prism in each lens should also be balanced for binocular viewing. ***Corresponding areas in the two lenses should provide a similar level of vision.
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12. Why Use Progressive Lenses? Bifocal lens Progressive lens The bifocal lens (left) can disrupt the patient’s view with visual disturbances (arrows) when the eye crosses the boundary of the near seg. The progressive lens (right) has no such problem and enables a smooth transition between different reading distances.
23. Width of Far V ision (+4mm): 0.5 [D]- 16.2 mm 1.0 [D]- Unlimited Max Cylinder [D]- Nasal: 1.5[D] Max Cylinder [D]- Temporal: 1.5 [D] Width of Corridor (-6mm): 1.0[D]- 9 mm Length of corridor: 14.2 mm Minimum fitting: 19 mm Width of near Vision (-18 mm): 1.0[D]- 21.63 mm Soft Design
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29. Progressive Lens Design 3. Symmetrical Vs Asymmetrical Symmetrical PAL - same lens design is rotated to fit the other eye Asymmetrical PAL - each eye has a different lens
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48. Computer lens 12 mm power transition zone Access uses a unique aspheric surface: Upper portion for mid-range distances Lower portion has reading Rx Power varies smoothly from top to bottom Mid-range Near
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50. mc compared to Adult Progressive Lenses Addition Power Plot mc Myopia Control Standard Adult Progressive Short Corridor Adult Progressive
52. R1 Far Zone Rn Progressive Zone R2 Near Zone Controlling the distortion is the key to the ultimate progressive lens Topographic Map Minimizing Distortions
53. The technology that enables us to design progressive lenses through an exact simulation of the natural human eye view. Eye Point Technology
54. The optical power is created by 3 parameters: thickness, index and curvatures The surface of the lens is scanned by a 3D measuring system, mapping the curvatures of the lens. Eye Point Technology
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