Reflex Pupillary

The pupillary reflex is one of the important human reflexes. It lies in the fact that when light hits the eyes, the pupils narrow, and when there is no light, they dilate. This reflex allows a person to adapt to changes in light levels and protect the eyes from bright light.

The pupillary reflex is regulated by the brain, which receives signals from the eye. When light hits the eye, the brain sends a signal that causes the pupil to constrict. This occurs due to the contraction of the muscles that control the size of the pupil.

In addition, the pupillary reflex may be impaired in certain diseases such as glaucoma, cataracts and others. In such cases, the pupil may remain dilated even in the absence of light, which can lead to poor vision.

Thus, the pupillary reflex is important for the normal functioning of the eye and human vision. Its violation can lead to serious consequences, so it is necessary to monitor the condition of the eye and consult a doctor if necessary.

The pupillary reflex (r. pupillaris) is a reflex reaction of the pupil to a change in the light flux, which occurs due to contraction or expansion of the muscles of the iris. Normally, when the light flux increases, the pupil narrows, and when it decreases, it dilates. The pupillary reflex is an important element of the visual system and ensures that the eye adapts to changes in lighting.

The pupillary reflex is regulated by the autonomic nervous system and consists of contraction or expansion of the iris muscle. When the luminous flux increases, nerve impulses are transmitted to the parasympathetic nervous system, which leads to contraction of the iris muscle and constriction of the pupil. When the light flux decreases, nerve impulses enter the sympathetic nervous system, causing the pupil to dilate and increase the amount of light entering the eye.

Impaired pupillary reflex can be associated with various medical conditions, such as glaucoma, retinal detachment, brain injury, diabetes, and certain medications such as antidepressants and antihistamines.

In addition, the pupil reflex plays an important role in the diagnosis of eye diseases, for example, during fundus examination, when the doctor assesses the condition of the pupil, its size and shape.

Thus, the pupillary reflex is an important component of the human visual system and plays a key role in adapting the eye to different lighting conditions.

The pupillary reflex is an involuntary and protective mechanism that allows the pupil to rapidly constrict when bright light hits the retina. This usually occurs within a few seconds of the flash of light. The pupil contracts to a small aperture, which allows less light to pass through and reduces its brightness. This helps protect the retina from damage and preserve its ability to see properly. Thus, the pupillary reflex serves to protect the human visual system in hazardous conditions. This mechanism is present in most mammals and birds, but not in some reptiles and fish.

There are congenital and acquired disorders of the pupillary reflex. For example, a birth defect - anisocoria - is a condition in which the pupils are different in size. Acquired disorders occur with certain diseases and injuries. For example, akinesia of the visual analyzer, when there is no reaction of the pupil to a change in the light flux; accommodative innervation, where the pupil stops stretching.

The cause of congenital pathologies is a violation of the neurohormonal balance and pathology of refraction. Most often caused by tumors of the nervous system or toxic poisonous substances. With injuries to the visual analyzer, hysterical paralysis most often occurs, causing pathologies of the pupils.