Why do we blink?
Blinking is a normal reflex that protects the eye from dryness, bright lights, foreign objects, fingers, or other debris coming towards it. Blinking also regulates tears which nourish and cleanse the surface of the eye. The blinking rate in newborns is only 2 times per minute. This increases to 14-17 times per minute in adolescence and remains at this rate through the remainder of life. Blinking can also increase in response to pain, bright light, changes in temperature and humidity, and conversation.
What causes excessive blinking?
Excessive blinking can be caused by problems with the eyelids or anterior segment (front surface of the eye), habitual tics, refractive error (need for glasses), intermittent exotropia or turning out of the eye, the environment (changes in temperature or humidity, bright lights, or pain), and stress. It is very rare for excessive blinking to be a sign of an undiagnosed neurologic disorder.
How can excessive blinking be evaluated and diagnosed?
A pediatric ophthalmologist will be able to diagnose the cause of the symptoms. A thorough exam will be performed. If there is a problem such as an ingrown eyelash, corneal abrasion (scratch on the front surface of the eye), conjunctivitis (pink eye), foreign body in the eye, or allergies affecting the eye or eye dryness, this can easily be diagnosed by performing an examination with an instrument called a slit lamp. This is a special microscope used to magnify the eye. If glasses are needed, this can also be easily detected though many times requiring a dilated eye exam. Any strabismus (in turning or out turning of the eye) will be diagnosed when the ophthalmologist examines the eye movements.
How is excessive blinking treated?
If an abrasion or conjunctivitis is diagnosed, eye drops or ointment may be given. Glasses may be prescribed if the excessive blinking is caused by blurry vision. The treatment will depend on the reason for the excessive blinking. If the complete eye exam is normal, the family may be reassured and recommended to monitor the symptoms.
What is a habitual tic?
A habitual tic is a small, semi-voluntary body movement. It may be caused by stress, fatigue, or boredom among many other causes. It usually affects both eyes at the same time. It affects boys twice as often as girls with the average age of starting symptoms around 5 years. It is a benign condition that will resolve without treatment usually within weeks to years though often recurring intermittently. There is no neurologic cause and further evaluation with brain scans are not necessary. If the child displays multiple tics and/or auditory (vocal) tics than an appointment with a neurologist is indicated. Once an ophthalmologist has determined that a child does not have an eye problem, it is best for parents not to draw attention or discuss the excessive blinking as the symptoms tend to diminish on their own. Habitual tics that persist should be discussed with the child’s pediatrician who may be helpful in identifying ways to manage stress, anxiety, or other possible triggers.