----------------------------------------------------------------------------------------------- Auto Ref/Keratometer CRK-8800 55
MIX : “-“ sign will be attached in the case of the myopic astigmatism whereas, “+” sign in the
case of the hyperoptic astigmatism.
The above-mentioned option can be chose in ‘User Setup Mode’
(4) Axis
Axis is expressed counterclockwise from the ear side of the left eye as the origin shown in the
figure below.
(5) Pupil Distance (PD)
Pupillary distance (PD) is the distance between the centers of the lenses of glasses.
Conveniently, it is said that the distance between the pupils is the distance between the center
of two lens.
Average PD of Korean people is about 62 or 63mm for men and about 60mm for woman.
