Range of diopter measurement
from 0D to ±20D
Minimum scale value
0.125D at 0D to ±5D, 0.25 at ±5D to ± 20D
Astigmatism axis of cylindrical lens
0 to 180°, minimum scale value 5°
Prism base angle
0 to 180°
Regulation of ocular visibility
±5D
Overall dimensions of device
46*17*24 (CM)