Tangent Screen provide a very accurate of charting the central and Para-central field of vision. They are an invaluable aid in diagnosing pathological conditions. Testing may be done at one meter or two meters with the appropriate screen. We use the best black felt available to insure non-reflectivity. All markings are stitched in semi-visible black thread showing concentric circles, radial lines and blind spots. These markings insure ease of testing, scoring and transcribing the mapped fields for visual field analysis. A white Fixation button is attached. Special orders can be filled for white or red thread. Tangent Screen come in a roll-up style and measure 43" x 43" (1.1 m x 1.1 m).