Bacteria. Bacteria are one-celled organisms visible only with a microscope. They're so small that if you lined up a thousand of them end to end, they could fit across the end of a pencil eraser. Not all bacteria are harmful, and some bacteria that live in your body are helpful.For instance, Lactobacillus acidophilus â a harmless bacterium that resides in your intestines â helps you digest food, destroys some disease-causing organisms and provides nutrients.acteria are one-celled organisms visible only with a microscope. They're so small that if you lined up a thousand of them end to end, they could fit across the end of a pencil eraser. Not all bacteria are harmful, and some bacteria that live in your body are helpful.
Optic atrophy is the final common morphologic endpoint of any disease process that causes axon degeneration in the retinogeniculate pathway. Clinically, optic atrophy manifests as changes in the color and the structure of the optic disc associated with variable degrees of visual dysfunction. Optic atrophy is actually a misnomer; in the strict histologic definition, atrophy refers to involution of a structure resulting from prolonged disuse.
Optic nerve atrophy Definition. Optic nerve atrophy is damage to the optic nerve. The optic nerve carries images of what the eye sees to the brain. Alternative Names. Optic atrophy; Optic neuropathy. Causes. There are many causes of optic atrophy. The most common is poor blood flow. This is called ischemic optic neuropathy. The problem most often affects older adults. The optic nerve can also be damaged by shock, toxins, radiation, and trauma. Eye diseases, such as glaucoma, can also cause a form of optic nerve atrophy. The condition can also be caused by diseases of the brain and central nervous system.