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The Combination Horizontal Vertical Prism Bar provides accurate measurement of ocular deviation. This new 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. Prism bar can be used alone or together.
The prism bar is precisely calibrated for dual use and helps voids variable strabismus results. The bar measures primary and secondary deviations.