In 1998, American association of optometrists has entered the new term called computer vision syndrome. It is a complex of visual and eye symptoms caused by work on computer.
According to different data:
- on average about 60 percent of all users complain of sight impairment;
- every sixth patient passing ophthalmologic inspection had problems connected with work on the computer;
- 22 percent working at the computer also have accompanying complaints to discomfort, neck, back, shoulders pain, manifestation of carpal tunnel syndrome.
Computer Vision Syndrome Causes
The popular belief in existence of pathological influence of radiation from video display of terminals on human body is exposed to criticism now. Some sources confirm lack of gamma and high-frequency radiation from monitors, and radio-frequency and ultra-violet — have levels below maximum permissible norms. However, women working with monitors have data on increase in spontaneous abortions, it is also reported about increase in quantity of skin diseases (seborrheic dermatitis, acne, heterospecific erythema and etc). The divergence of researchers’ opinions testifies to insufficient study not only to monitors’ radiation presence, but also consequences of its impact on human body in general.
One of the main causes for computer vision syndrome development is a qualitative difference of image on monitor and on paper. The picture on the monitor is:
- self-shining, but not reflected;
- less contrast;
- discrete (consisting of pixels);
- flickering (it is characteristic of monitors with an electron beam tube);
- has no accurate contours.
The human vision system is adapted for objects perception in reflected light. If you do not have a pretty good idea how to protect yourself from computer vision syndrome you are welcome on Canadian Health&Care Mall to find the necessary answers about how to maintain your eye health conditions.
Symptoms emergence of computer vision syndrome is connected also with the wrong ergonomics of workplace.
A negative role is played by the following factors:
- wrong position of user in relation to monitor;
- wrong arrangement of monitor in relation to external sources of lighting (existence of light patches on screen);
- excess or insufficient illumination in room;
- discrepancy of monitor technical parameters required for a long safe work;
- features of work with computer (need of gaze turn from the screen on the keyboard and the text on paper);
- organism’s physiological features (insufficient cornea moistening because of strengthened evaporation of tear at eye blink reduction).
The major factor influencing development of computer vision syndrome is the look corner. The look corner (α) is a corner between the lines connecting the center of the monitor to an eye(s) and horizontal. Decrease in frequency of symptoms development is noted at angel of more than 14 degrees.
The healthy person in a minute does, on average, 18 eye blick movements. Researches have shown that at computer users their frequency decreases to 4 times in a minute.
Development of a computer vision syndrome can indirectly be promoted by associated diseases, such as:
- carpal tunnel syndrome;
- Parkinson’s disease;
The diseases of thyroid gland which are followed by expansion of palpebral fissure and violation of correct eyelids condition can lead to strengthening of tear evaporation. Application of anti-cholinesterase, antihistaminic, diuretic medications and antidepressants can reduce amount of plaintive liquid. All this, in turn, can cause development of computer vision syndrome characteristic symptoms.
Computer Vision Syndrome Symptoms
The computer vision syndrome is manifested by rather characteristic symptoms:
- decrease in visual acuity;
- visual blur;
- difficulties when turning a gaze from near objects on distant and back;
- the seeming change of objects coloring;
- doubling of visible objects;
- “goosebumps” and darkening in eyes;
- excess light sensitivity;
- decrease in visual working capacity;
- visual exhaustion.
Eye symptoms include:
- pain in eye-socket and forehead;
- pain at the eyes movement;
- eyeballs reddening;
- feeling of sand under eyelids;
- smarting eyes;
- dry eye syndrome;
- “sandpaper” in the eyes.
If you are working constantly at computer you should protect yourself from unwanted ramifications. Control your working capacity with known methods of computer vision syndrome treatment online.