Blurred vision is a symptom that can be associated with a number of medical conditions. Initial evaluation of this symptoms is best accomplished by consultation with your pediatrician
or family medicine doctor
Most commonly, blurred vision in the setting of coughing is caused by excessive tearing. The mechanism of throat irritation that leads to excessive coughing has a number of additional effects, including causing the production of excess tears and mucus.
Blurred vision can also be associated with fatigue or a systemic illness
, such as an infection. If the cough is a symptoms of a more serious general illness, such as a lung infection, then blurred vision might be an additional symptom.
Additionally, many cough and cold medications contain compounds that can cough blurred vision. Because of these and other concerns about side effects, it is generally recommended that over the counter cough and cold medications should not be given to children.
Extremely rarely, cough and blurred vision together might be a sign of a serious neurological problem such as a brain tumor.
As always, the diagnosis and management of your son's specific condition will require a physical examination by your personal physician. If there are any persistent symptoms, scheduling an appointment with your pediatrician or family medicine doctor is highly recommended.