Why pupils are dilated: causes and consequences

The pupil is a round hole in the iris of the eye, a kind of diaphragm that can change its diameter. Sensitive photoreceptors of the eye react with unbelievable accuracy to changes in the flux of light rays. Depending on the intensity of the lighting, the special muscle reduces or increases the size of the hole, thereby regulating the amount of light falling on the inner shell - the retina. The change in the diameter of the pupil is one of the most important indicators of the function and general state of the brain. It is not for nothing that in any feature film devoted to emergency medicine, you can see how a doctor shines a narrow flashlight in the eye of the patient in order to cause a reflex narrowing of the pupil and to assess the level of consciousness.

The change in the size of the pupil can be associated not only with the degree of illumination. For example, when a person sees something that causes a heightened interest, the pupil changes its size intensely.

If the pupils are dilated, the reasons for this can be the following: strong emotions, excitement, increased attention, pain, fear. But there is also a painful permanent enlargement, which eventually leads to the defeat of the optic nerves.

Pupil and Disease

Persistent expansion of the pupils of the physician is called mydriasis. This condition can be caused by medications or potent chemicals (including drugs).

However, doctors say that if the pupils are enlarged, the reasons need to be determined as quickly as possible. Mydriasis can cause trauma (both the eye itself and the brain), as well as stroke, epilepsy and a number of other brain diseases. However, at different ages the reasons for the persistent changes in the size of the pupils are different. If the adult pupils are dilated, the causes of this phenomenon can be covered in lesions and diseases of the cerebral vessels.

But if it is observed in newborns and young children, you should not always worry. If the dilated pupils in the child are noted, the causes of this phenomenon can be covered in congenital genetic features. It is noteworthy that the pupils of the newborns are of different sizes. In most cases, you should not worry. But if the pupil is enlarged by more than 1 mm and under the influence of light to the original size does not return, then this is an occasion to consult a doctor.

Midriaz in a teenager is a sign of trouble

As mentioned above, the change in pupil size is caused by drugs like cocaine, LSD, marijuana, amphetamines and other deadly substances. If the dilated pupils of the adolescent, the reasons for this, as a rule, are impartial. A persistent change in the size of the pupil in the direction of increase is regarded as a physiological sign of drug use. However, parents and teachers should remember that the opposite phenomenon (persistent narrowing of the pupil) is also a sure sign of intoxication with drugs of the opiate group. The pupil is unusually narrow and does not expand at all in complete darkness. But in teenagers the pupils can also be dilated due to illness. Do not forget about the fact that mydriasis allows you to suspect a disease of the nervous system or blood vessels. In addition, the pupils of different sizes - this is an early sign of brain tumors or severe infection.

If you notice that you or your family members are dilated, the reasons should be determined as soon as possible. Wide pupils give beauty to the eyes, but they can also signal about trouble and illness.