Reflex Pupillary Pain

The pupillary pain reflex, or the pupillary reflex in pain, is the reaction of the pupils to a painful stimulus. Patients reflexively try to close their eyes, as if to protect them from light and thus reduce the pain. With painful stimulation, two most significant components are observed: the first phase – dilation of the pupils; the second phase is a spasm of accommodation (involuntary reduction of the eyes to the nose).

Reflex of pupillary changes during painful stimulation (M. Pupillarius, Sick reflex) - a change in the size of the pupil after mechanical action or unexpected painful stimulation, caused by the expansion of peripheral blood vessels. A painful stimulus first causes a sharp constriction of the pupil due to a reflex reaction to disruption of the internal organs and changes in pressure inside the eye, then a long-term expansive paralysis of the parasympathetic nervous system occurs, as a result of which the pupil expands in diameter.

The larger the area of ​​influence of the pain factor, the more pronounced the reflex is.

Initial condition – 2-3mm. There are 4 phases of the parabiotic effect of pain: - constriction phase - the pupil is reduced to 2-3