Visual field loss (or visual field cut): The visual field is the total area that can be seen while focusing on a central point. Each eye has receptors called rods and cones; they are located in the retina, at the back of the eye. The cones (which handle color and reading vision) are predominately in the center of the retina, in area called the macula; the rods (which handle black-and-white and night vision) predominate in the periphery of the retina. When stimulated by light, all of these photoreceptors send impulses to the occipital region of the brain, via the axons of the optic nerve. Damage to specific photoreceptors or axons will result in a visual field loss corresponding to the damaged receptors. A patient with a visual field loss may or may not notice a hole (i.e., missing area) in their vision.
Visual field loss (or visual field cut) medical expert witness specialties include ophthalmology, ocular trauma, and neuro ophthalmology.