Pupillary Reflex, Light Reflex

The pupillary reflex and the light reflex are two important reflexes associated with the eyes. They occur in response to changes in light levels in the environment and lead to changes in the size of the pupil, the hole in the center of the iris. These reflexes help regulate the amount of light entering the retina and protect the eyes from overexposure to bright light.

Pupil reflex
When the retina is exposed to bright light, the parasympathetic nervous system is stimulated, causing the muscles of the iris to contract. This causes the pupil to become smaller as the muscles of the iris squeeze the opening. This reduces the amount of light entering your eyes, which helps protect them from damage.

Light reflex
When dim light enters the eyes, the sympathetic nervous system is activated, causing the pupil to dilate. This increases the amount of light that can reach the retina. This reflex also helps protect the eyes from loss of vision in low light conditions.

Both reflexes are important for maintaining normal eye function and vision. Impairment of these reflexes can lead to various eye diseases such as nearsightedness and farsightedness. Therefore, it is important to monitor the condition of your eyes and undergo regular medical examinations.

Pupillary reflex
The pupillary reflex is the ability of the pupil to adapt to changes in the amount of light entering the retina. This reflex is one of the main mechanisms for regulating eye light and maintaining normal vision.
When bright light hits the retina, the parasympathetic part of the autonomic nervous system is excited, causing the pupil to constrict. This occurs due to a decrease in the number of nerve impulses entering the parasympathetic ganglia and a decrease in the release of acetylcholine, which causes contraction of the iris muscle. Thus, the pupil contracts and lets in less light, which reduces its brightness and protects the retinal photoreceptors from damage.
If the light becomes dimmer, the sympathetic nervous system is excited and releases norepinephrine, which causes the pupil to dilate. A dilated pupil allows more light to pass through and allows you to see better in dim lighting.
Thus, the pupillary reflex plays an important role in maintaining normal illumination of the eye and ensuring clear vision.

Introduction The visual reflex or pupillary reflex reflects the functional state of the oculomotor and other parts of the central nervous system (CNS), as well as the reaction of the optic nerve, muscle tone of the iris, lens and vitreous body. It is determined by the dilation or constriction of the pupils in response to the inclusion of a photogenic stimulus.

**Pupillary reflex** is considered as the simplest and most reliable of