Medical Deals Auto Refractometer features a spherical measuring range of -20D to +20D and a cylindrical range of -8D to +8D, with 0.12D or 0.25D steps. It includes a 45-88mm pupil distance and a minimum pupil size of Ø2.0mm. The device also uses a colorful fogging chart system for precise readings. Login Login 0 repins 0 comments 0 likes