Alden HP Sphere

HP SPHERE PRODUCT
 
  Materials Diameter Base Curve Sphere
ALDEN
HP SPHERE
HP 49
lens material of first choice
OR
HP59
for extreme dry eye
ANY
AVAILABLE

14.5 suggested
ANY
AVAILABLE

8.3, 8.6, 8.9
suggested
+30.00 to -30.00
in 0.25 steps
    No additional charge
for any diameter or base curve
outside of this range
 

Empirical Fitting Guide

Diameter Selection

  • Use the 14.5 diameter for normal-sized corneas
  • If a different diameter is desired, add 3.5 mm to the HVID to calculate the lens diameter

Base Curve Selection

  • Use the chart to select the base curve based on the diameter and average K reading

Power Determination

  • Use standard vertex adjustment to convert the spectacle Rx, or call our consultants and let us do it for you

Adjustments (when necessary)

  • When evaluating the fit of the lens, please provide our consultants with the following data:
    • Fit/movement (base curve evaluation)
    • Lens overlap (diameter evaluation)
    • Orientation, in 1° increments if possible
    • Over-refraction
  • We’ll calculate the Rx for you
BASE CURVE SELECTION CHART