Excellent for measuring:-

Fusional Reserves – which can help in your diagnosis of binocular vision problems.

Phorias & Squints – which can improve the accuracy of your estimations & monitoring.

Box comprising a Horizontal and a vertical prism bar

Vertical Prism Bar:-

Vertical prism bar, with 1/2/3/4/5/6/8/10/12/14/16/18/20/25D

Horizontal Prism Bar: -
Horizontal prism bar with 1/2/4/6/8/10/12/14/16/18/20/25/30/35/40D