The VT-1 Vision Tester provides exceptional quality and value, featuring quick, easy and accurate refractions. Notable features include synchronized cross cylinders, an extended measurement range, and multi-coated lenses. Item and range Of measurement (the value in ( ) with accessory lens or auxiliary lens attached): Myopia0 to -19.00 diopter in 0.25 diopter step (0.12 diopter step) Hyperopia0 to +16.75 diopter in 0.25 diopter step (0.12 diopter step) Astigmatism0 to -6.00 diopter (-8.00 diopter) in 0.25 diopter step (0.12 diopter step) Phoria and vergency20 to 0 to 20 by 1 step Inner 40 Outer 40 (50 ) Upward and downward 40 (60 ) Near vision test Main optical axes of both lenses converges by means of a tilt mechanism at 40cm in front of the eyes at 64mm P.D. If P.D. for far vision is less than 54mm, converging operation stops. Binocular balance Test Rotary prism and polarizing lens methods are available. P.D. 48 to 75mm by 1mm step Level adjustment More than 4.5° for right and left banks Dimensions 64mm P.D. setting) × 97 × 294mm Weight4.5 kg a