Range of measurement：
Minimum scale value： | 0 to±20D |
0.125D graduation up 0 to±5D
and 0.25D graduations over±5D to±20D |
Astigmatism axis angle of cylindrical lens： | 0~180°step 5° |
Prismatic Power Range： | 0-20△ prism diopters, 1△ graduations |
Prism basal angle： | 0～180°Minimum scale value 1° |
Range of ocular visibility adjustment： | －5D～＋5D |
Size of measured lens： | φ30mm~φ90mm |
Lamp of illumination： | 220V / 110V 15W |