Perimeter

Perimeter: Determining a person's field of vision

A perimeter, also known as a visual field tester, is a tool that is used to evaluate a patient's visual function. It allows you to determine the field of view and identify any defects in it. The perimeter is commonly used in ophthalmology and neurology to diagnose various diseases related to the visual system.

The principle of operation of the perimeter is based on the fact that the patient fixes his gaze on the target located in the center of the inner surface of the hemisphere. Then a moving object appears on the target, and when the subject notices it, he reports it to the doctor. This way it can be determined how far the patient can see in different directions and any defects in the visual field can be identified.

There are several types of perimeters. In a static perimeter, a moving object is replaced by a system of tiny light sources set against a dark background. This allows the patient to see their light better. If the patient has any distortion of the visual field, he will not be able to distinguish light from sources that are located on the side of the affected area of ​​the eye. In kinetic perimeter, an object is moved across a target at different speeds to determine how far the patient can see in different directions.

In modern conditions, computer diagnostics are often used to determine the visual field, with the help of which even the most minor visual field defects can be very accurately identified. This method is called computerized perimetry. In computer perimetry, the patient looks at a screen on which points of light appear. When he spots a dot, he presses a button. The computer records how far the patient can see in different directions and creates a map of the visual field.

The perimeter is an important tool for determining visual function and identifying visual field defects. Modern computer perimetry technologies make it possible to obtain more accurate data and process results more quickly. This helps doctors quickly and accurately diagnose eye and nervous system diseases related to visual function.

A perimeter is a device that is used to determine a person’s field of vision and identify defects in it. This diagnostic method is very important for assessing the condition of the fundus and identifying various pathological changes in visual functions.

The perimetry procedure is based on the following principle: the patient fixes his gaze on a target located in the center of the inner surface of the hemisphere. Then a moving object appears on this target, and when the subject notices it, he informs the doctor about it. In this way, a person's field of vision can be determined and any defects in it can be identified.

There are several types of perimeters, but the most common are static and computer perimeters.

A static perimeter uses a system of tiny light sources set against a dark background so that a person can clearly see their light. If the patient has any distortion of the visual field, he will not be able to distinguish light from sources that are located on the side of the affected area of ​​the eye.

Computerized perimetry is a more modern method that uses computer technology to determine the field of view and identify defects in it. In this case, the patient looks at a computer screen on which various objects appear. In this case, the doctor can precisely control the parameters and characteristics of the test and obtain more accurate results.

Computer perimetry allows you to determine even the most minor defects in the visual field and is the most accurate method for diagnosing diseases of the eyes and nervous system associated with vision.

The perimeter is an important tool for assessing a person’s visual functions and identifying various pathological changes in his visual system. Thanks to the use of modern technologies, such as computer perimetry, doctors can obtain more accurate results and effectively treat patients with diseases of the eye and nervous system.

Perimetry or the perimeter method is widely used by doctors in ophthalmology, neurology and ophthalmic surgery. The essence of the method is to determine fields of view and study defects. Visual fields are determined in degrees of the horizontal and vertical circle, i.e., the peripheral parts of the retina, which make it possible to clearly distinguish objects. Peripheral vision covers 35% of the coverage from the fixation point. An ophthalmologist checks 3,000 per day