Light Reflex

Light reflex (Light Reflex) - see Pupillary reflex.

The pupillary reflex is a reflex in which the pupil of the eye contracts when bright light enters it and dilates when it is dark or dimly lit. This reflex allows the eye to adapt to changing lighting conditions, allowing it to optimally use the available light to form a clear image on the retina.

The pupillary reflex is regulated by the autonomic nervous system. When light hits the retina, retinal cells are excited, which send nerve impulses to the brain. From there, impulses go to the oculomotor nerve, which innervates the orbicularis iris muscle. Contraction of this muscle causes the pupil to constrict. In the dark, the process goes in the opposite direction - relaxation of the iris muscle leads to dilation of the pupil.

Thus, the Light reflex, or pupillary reflex, allows the eye to function effectively in different lighting conditions by changing the diameter of the pupil.

What is the light reflex? The fact is that its name speaks for itself. In natural light, a person's pupil contracts less than in artificial light. That is why the body’s response to a change in lighting is called the pupillary reflex (Schieber reflex). Also, in bright light, the appearance of “naked” pupils not protected by eyelids (so-called retinoscopy) or drying out of the cornea of ​​the eyes and even sometimes loss of vision for some time is possible. These factors are quite easily preventable if you follow a number of rules: • when changing lighting, do not immediately switch from light to darkness, since the reaction is always much weaker than vice versa. • when working indoors, it is recommended to use all kinds of lamps. • reduce the brightness as much as possible in your limit position.• avoid in the dark