Right angle prisms knife Mirror are generally used to bend image paths or redirect light at 90°. This produces a left handed image and depending on the orientation of the prism, the image may be inverted or reverted. Right angle prisms can also be used in combination for image/beam displacement. UV Fused Silica Right Angle Prisms are made from UV fused silica which features low thermal expansion and excellent transmission throughout the UV, visible, and NIR spectral ranges.