Tag: blinking

Digital Eyestrain

Karen Griffith

 

A 2016 report by the Vision Council found that 60% of Americans use digital devices for 5 or more hours each day. 70% of Americans use 2 or more devices at a time.
The term Digital Eyestrain has replaced the term Computer Vision Syndrome due to the increase in types of digital devices. Digital Eyestrain is defined as “physical discomfort of one’s eyes after spending periods of time throughout the day in front of a digital device, such as a computer or smartphone.”

The list of Digital Eyestrain symptoms is long:

Eyestrain, Burning Eyes, Difficulty Refocusing, Grittiness, Dry Eyes, Blurred Vision, Headaches, Irritation, Tired Eyes, Neck/Shoulder/Back Pain, Double Vision, and Redness.

It is reported that we blink an average of 10 times a minute normally, when reading, using a smartphone or other device the blink rate drops to 4 times a minute. Blinking is a vital component to ocular surface health and tear stability. More important than how often we blink is how well we blink. An incomplete blink can cause more tear instability than not enough blinks. A complete blink is necessary to stimulate a muscle on the eyelid margin that releases an important component of the tear film.

Treatment for Digital Eyestrain includes wearing the best visual correction for the task. Reducing glare and fatiguing light with coatings is beneficial also. For contact lens wearers the proper correction for the working distance is important. A clean contact lens surface and proper blinking can minimize dry eye symptoms.

Why do we Blink?

Karen Griffith

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Blinking cleans the ocular surface of debris and flushes fresh tears over the ocular surface. Each blink brings nutrients to the eye surface structures keeping them healthy.
Human are meant to blink. Not only are we meant to blink, but we are meant to blink in a particular way and at a particular frequency that ensures the renewal and revitalization of the front surface of the cornea and conjunctiva.
Blinking cleans the ocular surface of debris (dead cells, mucus and the junk that blow in the wind). It rinses fresh tears over the ocular surface. The fresh tears bring nutrients and other substances to the surface structures keeping them healthy. It helps prevent infection and clears and brightens the image received by our retina. Blinking wets the outer eye and in the case of a contact lens wearer, replenishes the tear layer upon which the contact lens floats.

Normally, a blink brings tears from the lacrimal gland which is located above the eyeball and under the brow bone, and sweeps them across the eye surface. Infrequent and incomplete blinks cause the surface of the eye to “dry” between refreshing tears. A few things will cause us to blink less often – staring at a computer for example. The blink rate slows down when reading or concentrating on a task. Paying attention to our blink rate can decrease dry eye and discomfort.

Lid structure and bad habits can prevent us from closing the eye completely with each blink.  After an incomplete blink the lower part of the eye is left exposed and without fresh tears. This is called “lagophthalmos.” Some people sleep with the eye partially open causing dessication (dryness) of the lower portion of the cornea. Not only is this uncomfortable, but can cause scarring. Nighttime lubricants and habit changes are often required to prevent complications from lagophthalmos.

Pay attention to how often you blink and how you blink. Make sure your eyelids meet with each blink and that you avoid starring when concentrating on a task.