Interestingly, for completely different reasons, the pupil may increase to 4 times. What are the reasons?
Drugs
Most often, the pupils dilated using eye drops, but some pills have the same side effect. Therefore, it is necessary to pay attention before they eat (this property is usually specified in the column "Side effects").
Darkness
When a person enters the dark room, the pupils dilate so the area of the perception of vision increased and partially compensated the lack of adequate lighting.
Fear
The muscles located in the iris react to fear, activated the parasympathetic nervous system reflex and the pupil expands. The same happens during times of stress and nervous breakdowns.
Bad habits
Alcohol abuse, Smoking, intake of narcotic and psychotropic substances can always be recognized by the advanced pupils of the person. This is due to the fact that the brain is not receiving sufficient oxygen.
The pain and shock
In case of serious damage, such as fractures or injuries in the body release adrenaline (the stress hormone). This is what provokes an increase of the pupils.
Excitation
When dealing with the opposite sex, which is accompanied by sympathy, people pupils dilate. This is a sure sign, indicating that you are not indifferent person.
To be a secondary reason for the increase in pupils include arrhythmia, deep anesthesia, a sharp irritable factors (a sudden loud noise or bright light), interest in anything and a good mood. Life observation suggests that the slightly dilated pupils always present in people, balanced relating to the life and having a calm nature.