home *** CD-ROM | disk | FTP | other *** search
/ Contact Lens Series / Contact Lens Series Volume 1.iso / pc / keratom.dxr / 00171_Field_171.txt < prev    next >
Text File  |  1997-10-28  |  1KB  |  23 lines
  1.                   KERATOMETER MEASURING TECHNIQUE
  2.  
  3. Making the Power Measurement
  4.  
  5. Once the horizontal lines of the plus signs are 
  6. aligned, rotate the horizontal power drum (on 
  7. left side) until the vertical lines of the plus signs 
  8. are overlapping.  Next rotate the vertical power 
  9. drum (right side) until the minus signs overlap.  
  10. Be sure to overlap the mires as accurately as 
  11. possible.  It is often necessary to refocus the 
  12. mires during the measurement and between 
  13. reading the horizontal and vertical meridians.
  14.  
  15.                                                                                                     If the drum(s) are rotated 
  16.                                                   to their full extent and 
  17.                                                   the mires still do not align
  18.                                                   (the cornea is steeper or  
  19.                                                    flatter than the range  
  20.                                                    of the instrument), the                       
  21.                                                    range of the instrument 
  22.                                                    must be extended.
  23.