OPHTHALMOMETER MEASURING TECHNIQUE

Making the Power Measurement

Once the horizontal lines of the plus signs 
are aligned, rotate the horizontal power 
drum (on left side) until the vertical lines 
of the plus signs are overlapping.  Next 
rotate the vertical power drum (right side) 
until the vertical plus signs overlap.  Be 
sure to overlap the mires as accurately as 
possible.  It is often necessary to refocus 
the mires during the measurement and 
between reading the horizontal and 
vertical meridians.