Information on Factors That Cause the Eye to Blink

Blinking occurs naturally, approximately 10 to 15 times per minute with each blink lasting no more than one-tenth of a second. Blinking represents the body's way of spreading tears and other moisture across the eye. The tears and moisturizers clean the eye and remove foreign substances. Certain external factors or conditions affect the natural process of blinking.

Dry Eyes

• Dry eyes occur when the eyes do not receive enough moisture as the normal rate of blinking is not sufficient to lubricate the eyes. The body's compensation for dry eyes involves excessive blinking in an attempt to rectify the moisture imbalance. One condition that causes dry eyes is long periods in front of a computer screen. People tend to blink less when concentrating either on typing or reading from the computer. Over a period of time the failure to blink leads to dry eyes. If blinking does not restore sufficient moisture then eye drops may be required.

Benign Essential Blepharospasm

• Benign essential blepharospasm, or BEB, begins with excessive blinking that is not related to a lack of moisture in the eyes. Symptoms as the condition progresses include excessive squinting, light sensitivity and difficulty keeping the eyes open due to spasms. Eventually the eyelids close and will not reopen. This neurological disorder is not an eye disorder; the eyes work fine. They just remain shut all the time. At first, sleep corrects the problem and the eyes open upon waking, but eventually that does not work. The solution involves injections of botulinum toxins that relax the muscles, stop the spasms and allow the eyes to open. The injections are temporary and are repeated as necessary. Alternatives to the injections include medications or myectomy, a surgery that removes part of the muscle keeping the eye shut.

Allergies

• Any eye irritation produces blinking. The eye's defense mechanism attempts to eliminate the source of the irritation, whether a piece of dirt or an allergic reaction to some allergen. Spring and fall brings pollens from trees, grasses and weeds, which can irritate the eyes. Blinking becomes one of the lines of defense along with a runny or stuffy nose and sneezing. The eyes become red and irritated. Staying indoors as much as possible until the allergy season ends alleviates the problem. Allergies need not be seasonal; exposure to allergens like dog fur can prompt blinking and the other reactions.

Light Sensitivity

• A basic photography skill involves taking a picture of a person with their eyes open. Many people have a natural involuntary reaction to bright lights: they blink and close their eyes. When they are posing for a photograph, the body anticipates the coming light and reacts quicker than the photographer. One blink and the photograph reveals closed eyes. This light sensitivity also manifests itself when going from the inside of a building to the bright sunlight outside. The sudden bright light causes excessive blinking as the eyes adjust.

Tics

• Excessive blinking, especially in children, can be the result of a tic, which is an abnormal repetitive movement of muscles in the face. Normally, it is a transient occurrence that lasts a period of two to three months. As WebMD points out, tics can occur at any age and are generally harmless. Causes include stress and sleep deprivation. A tic is classified as an involuntary action, meaning the person can stop the tic by taking action, as opposed to an involuntary action where there is no control.