szemhatárok

Szemhatárok, also known as visual field or visual field defect, refers to the area of the visual world that can be seen by an individual at a given moment. It is determined by the position of the eyes, the shape of the orbit, and the curvature of the cornea. A normal visual field spans approximately 180 degrees horizontally and 135 degrees vertically, with a blind spot at the center of each retina known as the optic disc or macula.

Visual field defects can occur due to various conditions, including glaucoma, stroke, brain tumors, and multiple sclerosis. These defects can be classified as central or peripheral, depending on the location of the affected area. Central defects involve the central vision, while peripheral defects affect the outer edges of the visual field.

Visual field testing is a crucial diagnostic tool in ophthalmology and neurology. It involves measuring the extent and location of any visual field defects. The most common methods include automated perimetry, which uses a computer-controlled device to project stimuli onto the retina, and manual perimetry, which uses a handheld device to test specific points in the visual field.

Treatment for visual field defects depends on the underlying cause. For example, glaucoma may require medication or surgery, while stroke-related defects may not be treatable. In some cases, vision rehabilitation techniques, such as low vision aids and orientation and mobility training, may be beneficial.

Regular eye examinations are essential for detecting and managing visual field defects early. Early intervention can help preserve vision and improve quality of life.