Pupillary reflexes

Pupillary reflexes - involuntary contraction (or relaxation) smooth muscles of the iris, leading to the change of size of the pupil. There are pupillary reflex reaction (into the light, pain and friendly (on the accommodation, the convergence). Practical importance is the study of pupil reaction to light, pain and accommodation. The reaction of pupils to explore in front of a light box or other source of light; both eyes light evenly. Direct pupil reaction to light is determined, covering both eyes studied his hands, then, leaving one eye is covered, the other alternately opening, then cover with your hand. While covering his eyes watching the reaction of the pupil. Friendly reaction of the pupil of an eye to light explore, alternately dimming lighting and hand the second eye. At the moment lighting other eye pupil investigated eyes narrowed, while darkening expanding. The reaction of pupils on pain research, causing a slight prick on any area of the skin, when the atom is in norm pupils dilate. The reaction of the pupils at the accommodation determine approaching and removing from the eyes of any subject; studied should monitor roaming subject: at the moment of removal of the subject, the pupils dilate, the approach is narrowed.
Change the size, shape and the reaction of the pupils see some eye diseases and nervous system that affect pupillary centers or nerves Innervate the smooth muscles of the iris. The reaction of pupils can be sluggish, partially or completely absent, pupil size can be varied (anisocoria). In some diseases of the Central nervous system (tabes) pupillary response to light disappears, but is saved on the accommodation and convergence. Cm. also Eye Reflexes.