KERATOMETER MEASURING TECHNIQUE

Locating the Axis of the Corneal Toricity

The plus signs are aligned by 
rotating the body of the 
instrument by grasping it by 
the large ribbed ring in front 
of the eyepiece  and rotating 
it.  Rotate the instrument back 
and forth until the horizontal 
lines of the plus signs are 
aligned.

If there is no astigmatism 
the lines will always be 
aligned.  In this case make 
the measurement with the 
axes set at 180 and 90.