Worksheet 7: 

Spherical equivalent

  1. What is the circle of least confusion?

    2.  
  2. What is the relationship between the spherical equivalent and the circle of least confusion?

    3. What is the spherical equivalent for the following Rx's:

  3. +1.00 -1.00 x 180

    4.  
  4. -2.50 -1.50 x 045

    5.  
  5. +2.50 -1.50 x 145

    6.  
  6. +2.50 +2.50 x 020

    7.  
  7. +2.50 -5.00 x 175

    8.  
  8. pl -2.50 x 100

    9.  
  9. +6.50 sphere

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Textbooks:
Brooks & Borish, Systems for Ophthalmic Dispensing, 2nd Ed, Butterworth-Heinemann, 1996
Stoner, Optical Formulas Tutorial, Butterworth-Heinemann, 1997

Copyright 1998 - 2001, Ellen Stoner, MALS, ABOM, NCLC
Registered students may print one copy for study purposes.