The "cornea reflection light coincidence method" is      used.  This operates by aligning luminous points on      the pupils with the measuring line.

Results are displayed digitally.  Three measurements      are given : Right, right + Left, left.

Results are accurate to within 0.25 mm.

Measurements can be made for a single eye or for      both eyes.

Possible to measure PD of focusing-point distances      ranging from 30 cm to infinity.

Automatically switches OFF one minute after      operation is completed, thus conserving power.

Distances from tops of cornea to lenses of frames      can be measured.