Question: I-m confused about coding for visual fields (VF). The code description says "unilateral or bilateral." Would the coding and modifiers for a VF done on one eye be different for a VF done on both? Mississippi Subscriber Answer: Although the CPT definition for 92081-92083 (Visual field examination, unilateral or bilateral, with interpretation and report ...) seems to cover both bases, Medicare views visual field tests as inherently bilateral -- the optometrist usually performs the procedure on both eyes. For a bilateral VF test, do not append any modifiers. The payment from Medicare will reflect the work performed on both eyes. If the optometrist performed a VF test on only one eye, append modifier 52 (Reduced services) to 9208x.