71 m/m (Reverse Slab) Rd. 28 Bi-focal

 

Semi-Finished

Material: CR-39*

 

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

Segment Placement: 3m/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

(over 3.75 additions on quote)

 

1 Diopter Steps

 

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

 

71 m/m Extra Thick also available

 

 

Material: CR-39* Plastic                                                                       Specific Gravity: 1.32

Index of Refraction: 1.498                                                            Round 28m/m Reverse Slab

Abbe Value: 58                                                                                            71 m/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.-28       71m/m                  2.00           2.00               2.25         1.191         ***           ***               4.0        3.0

Rd.-28       71m/m                  4.25           4.25               6.25         2.573         ***           ***               4.0        3.0

Rd.-28       71m/m                  6.25           6.25               6.25         3.864         ***           ***               4.0        3.0

Rd.-28       71m/m                  8.25           8.25               6.25         5.240         ***           ***               4.0        3.0

Rd.-28       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.