The Combination Horizontal & Vertical Prism Bar provides an accurate measurement of ocular deviation. This combination prism bar resolves the problem by having the horizontal prism bar slide up and down in a channel affixed to the vertical prism bar. This ensures that the flat surfaces of both prism bars are held perpendicular to the direction of the fixation object. The prism bar can be used alone or together.

This prism bar is precisely calibrated for dual-use and helps void variable strabismus results. The bar measures primary and secondary deviations.