FRAME & FACIAL MEASUREMENTS

Boxed centre

intersection of the H&V lines of the rectangular box containing the lens shape

Horizontal lens size

distance between the H sides of the rectangle containing the lens shape

vertical lens size

distance between the V sides of the rectangle containing the lens shape

distance between centers

distance between the box centers

what is distance between centers also known as

frame PD

what does crest height measure

This measurement determines how high or low the frame sits on the face.

It is the distance between the lower eyelid and the nasal crest

what is a splay angle

This measurement determines the angle of the pad bridge or pad on arms in the horizontal plane

what is a frontal angle

This measurement determines the angle of the pad bridge or pad on arms in the vertical plane

what is bridge projection

This measurement determines how far away from the face that the frame
sits in relation to the eye lashes when they are in their most protruding
position

what is head width

This measurement is the horizontal distance from ear point to ear point

what is temple width

This measurement is the horizontal distance from temple to temple measured. The frame measurement is taken 25mm from the front

PANTOSCOPIC ANGLE/TILT

PANTOSCOPIC ANGLE/TILT
This measurement determines the angle of the sides of the frame when
the eyes are in the primary position of gaze