In the eye, the retinal nerve fibers transmit the visual signal from the photoreceptors to the brain. In certain diseases, i.e., glaucoma, these nerve fibers are damaged, resulting in impaired vision or blindness. The retinal nerve fiber layer consists of parallel structures of diameter smaller than the wavelength of light. Therefore, this qualifies it as a form birefringent structure, capable of changing the state of polarization of light double passing it. The amount of change in the state of polarization (retardation) can be assessed with a polarimeter and is proportional to the thickness of the nerve fiber layer at the measurement location. A scanning laser polarimeter (Nerve Fiber AnalyzerTM) is described that employs a low power near infra-red laser beam to illuminate the human retina. In normal eyes, a thick retinal nerve fiber layer was measured in the superior and inferior regions of the peripapillary retina. In glaucoma eyes, this normal nerve fiber layer thickness distribution was found to be disturbed. The measured retinal nerve fiber directions indicated that the retinal nerve fiber layer around the optic nerve head of a normal eye is radially symmetrical.