KERATOMETER MEASURING TECHNIQUE


Focusing the Mires

The headrest can be moved 
forward or backward with the 
small knob just below the 
patient's chin.  Turn the knob 
clockwise to move the patient's 
head back (when the focus 
control was all the way back 
towards the examiner and the 
mires still not in focus) and 
counter-clockwise to bring the 
forehead forward towards the 
instrument (when the focus control 
was all the way forward and the mires 
were still not in focus).