Prisms & Prism Bars

This red Maddox filter fits both the +/- 20 D and +/- 30 D Risley Prisms. ..

Large aperture (23mm) rotating prisms permit more flexibility than a Phoropter. This version is +/- 20 PD and has a convenient handle. The prism is controlled using a knurled rotating knob. The accurately calibrated dial shows prism diopter and rotat..

Large aperture (23mm) rotating prisms permit more flexibility than a Phoropter. This version is +/- 30 PD and has a convenient handle. The prism is controlled using a knurled rotating knob. The accurately calibrated dial shows prism diopter and rotat..

This prism bar has the range 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 25, and 30D.    This instrument is ideal for measuring fusional reserves - which may help in the diagnosis of binocular vision problems - as well as for measuri..