71 m/m (Reverse Slab) Rd. 22 Bi-focal

 

Semi-Finished: Material: CR-39*

 

Base Curves: 2.00, 4.25, 6.25, 8.25, 10.25

 

Segment Placement: 5m/m down & 4m/m in (Rights and Lefts)

 

Additions:

1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00, 3.25, 3.50, 3.75

 

1 Diopter Steps

 

1 to 20 Diopter Steps- 71m/m Right or Left

 

71m/m Extra Thick also available

 

 

Material: CR-39* Plastic                                                                         Specific Gravity: 1.32

Index of Refraction: 1.498                                                                  Rd 22m/m Reverse Slab

Abbe Value: 58                                                                                               71m/m Blanks

 

Note:**   Note:***

 

Lens                 Actual   Nominal    Actual             Back           Sag                                               Seg        Seg

Style                 Size            Curve     Curve           Curve       50m/m         C.T.           E.T.           Inset        Drop

 

Rd 22m/m       71m/m            2.00           2.00               2.25         1.191         ***           ***               4.0        5.0

Rd 22m/m       71m/m            4.25           4.25               6.25         2.573         ***           ***               4.0        5.0

Rd 22m/m       71m/m            6.25           6.25               6.25         3.864         ***           ***               4.0        5.0

Rd 22m/m       71m/m            8.25           8.25               6.25         5.240         ***           ***               4.0        5.0

Rd 22m/m       71m/m          10.25         10.25               6.25         ****       ****         ****           ****        ****

 

Note: **Over 5 Degrees of Prism Slab adds THICKNESS and changes ALL 71m/m BACK CURVES to -2.25.

 

Note: *** Center Thickness and Edge Thickness CHANGES with DEGREES of PRISM SLAB.

 

NOTE: ****Information Not Available At Press Time.