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Dry eye syndrome

Most computer users and people using contact lenses or working in an air-conditioned environment suffer from dry eye syndrome. It is a multifactorial disease of tears and the ocular surface. Common symptoms are: dryness, soreness, scratchiness, eye irritation, blurred vision, burning and even dilated blood vessels (red eyes) at later stages. If untreated for long period of time, it can even lead to eye damage. Dry eye syndrome affects 20% of the general population in Europe, North America and Asia [1]. Eyeblink is a complex solution to dry eye syndrome.

Healthy people blink 10 to 15 times per minute. While working at computer, a majority of users blink considerably less. Blehm et al. [2] observe up to a 60% reduction in blink rate. We have observed even up to 80% (it varies from person to person). The reason for our low blink rate has to do with the brightness of computer screen. It is similar to flames: we blink significantly less while looking into them. With a low blink rate, the tear film is not renewed and our eyes get dry.

[1] Benitez-del-Castillo, J.M., Lemp, M.A., Ocular Surface Disorders. Jp Medical Pub 2012

[2] BLEHM, C. et al. Computer Vision Syndrome: A Review. Survey of Ophthalmology. 2005, Available online.


Blinking matters

With each blink the tear film is renewed. Tear film consists of three sublayers: mucus, watery layer and oil layer at the top, which protects the eye from dryness (water evaporation). Tear film is a microscopic layer which protects and moisturizes our eyes. It is similar to flowers; without water they dry out. We could also compare it to a car engine which ceases without oil. Blinking matters! It washes out dust and microorganisms. Healthy people have a tear film layer 6 +/- 2.4 micrometers thick, compared to people with dry eye syndrome whose tears film has only 2 +/- 1.5 micrometers [3].

Each eye blink restores the tear film that protects our eyes.

Holland and Tarlow [4] say that blinking is related to cognitive processes. Blink rate is low during mental activities like solving arithmetic tasks or daydreaming. Blink occurs together with cognitive change. When solving arithmetic problems, we usually do not blink at all. As soon as we find the solution, we blink. Another example is reading. Most blinks occur at punctuation marks. In contrast, emotional excitement and frustration are related to a high blink rate. This is another reason to be careful; not only does monitor brightness decrease our blink rate but also mental tasks.

Environmental factors, such as air conditioning, fans, heating systems, low humidity, and dust, can also have a negative influence on the tear film quality. Contact lenses often reduce tear film quality. Some people do not fully close their eyes while blinking. As a result, their tear film is not fully renewed [5]. Optometrists and ophtalmologists often prescribe artificial tears. The problem is that artificial tears will never heal the disease; they just suppress the symptoms. The only way to recover from dry eye syndrome is to blink more. Eyeblink can help you with this.

[3] BRIGHTBILL, FS, McDONNELL, PJ, McGHEE, CH. Corneal Surgery: Theory Technique and Tissue. 4th edition, Pennsylvania: Mosby Elsevier, 2008.

[4] HOLLAND, M. K. – TARLOW, G. Blinking And Thinking. In Perceptual and Motor Skills, 1975, Available online.

[5] ROSENFIELD, M. Computer vision syndrome: a review of ocular causes and potential treatments. Ophthalmic and Physiological Optics. 2011, Available online.


Treatment

Light conditions are important aspect of eye care. Proper settings during day or night make it more comfortable for our eyes while working at a computer.

The best way, how to avoid dry eye syndrome is to blink properly, that is why Eyeblink should accompany you while working on computer. There are several other recommendations that can help you fight this disease. A warm eyelid massage delivers temporary relief from soreness. Just moisturize a handkerchief with warm water, put it on your eyes and massage. Focusing for long periods of time on objects at a close distance can be accompanied by headaches. Taking breaks and washing the eyes with cold water several times a day works great. After completing a small task, stand up from your computer, make a cup of tea or just look out the window. Taking small breaks (away from PC) after finishing a task will become automatic (like a reward). The 20/20/20 rule is very effective. After 20 minutes of work at computer, you should look at an object 20ft (6 meters) away for about 20 seconds. Taking small breaks is vital for maintaining eye health. Based on our observations (we recorded many people while working on our eye blink detection algorithm) people very often blink when they change their focus and look away from the computer screen.

Working environment is important; when possible, opt for matt screens. The screen should be 20 inches (0.5 meter) away from your eyes and at a 10-20 degree angle as illustrated in the picture. Light conditions are important - you should always adjust the brightness of your screen to be comfortable for your eyes (as eyeblink does). Natural light should come from the side; the window should not be behind or in front of the computer screen because of the contrast in lighting during midday or at night. During late hours, a room light or small lamp placed behind the screen will help to make lighting conditions more comfortable for our eyes.