In this age of information and advanced technology, the use of computer video display Units (VDUs) has become widespread. Nowadays, people and near vision task cannot be seperated. It is common in people at civilization country who are expose to the sedentary lifestyle. It is also common for the people who are from developing country which are not excluded from the near vision task syndrome. They are more likely have the near vison task syndrome especially when do the near work such as painting, sewing, and also on.
According to the chronology of the early human history, all men spent all day hunting and gathering or resting and sleeping, but by the seventeenth century 10% of men were sedentary workers and 90% were generally farm labourers. But times by times, in the twentieth century 90% of workers were engaged in desk work and only 10% were involved in manual activity or labour. It has been popular to believe that most of the diseases of modern civilization are due to the psychological stress of mental work, but in fact they are due to the tendency to sit at desks with poor posture and poor visual hygiene.
Although there is no good scientific evidence that computer use and near work damages the eye, the use of VDUs and a lots of near work everyday has always been associated with various eye symptoms. The symptoms like muscle tension, blurry eyesight, restless and stress are more likely happen upon this unhealthy lifestyle. In addition, inadequate awareness of VDU ergonomics and poor visual hygiene may contribute to ocular fatigue and other eye symptoms during VDU use and near vision task.
The concern about the potentially harmful effects of VDUs and near vision task on the human eye, however, has continued since the introduction of computers to the general population in the early 1980s. Therefore, expert always suggest that people must have the conciousness to take care of their hygiene in order to get rid of the unhealthy lifestyle effect. It is include the visual hygiene.
Visual hygiene is derived from the words visual and hygiene. Visual means that relating to used in vision for attaining or maintaining by sight meanwhile hygiene is define as a science of the establishment and maintenance of health. Visual hygiene generally practice among the people who are work with the computer, student that spend most of the time to study and also people who are dealing with the neat work especially painting, sewing, and also on. In visual hygiene, people always educate about the three things for instance maintain good posture, aligning the lighting of the task and also try to manage the focusing ability.
BODY OF CONTENT
There are a lots of things that people can do in visual hygiene. There are included the listed below.
a) HARMON distance
This distance is proven experimentally by Dr Darrel Boyd Harmon and subsequent research by Drs. John Pierce and Steven. He proposed that there is an intimate relationship between posture, working distance, desk surface and lenses. The proper reading distance are either elbow on our book or knuckles on our chin. It is approximately 35 to 40 centimeters in adults and less in children.
When people suffered from prolonged near visual task with inproper distance, it can induce visual problem. For instance, for those people who work with the too close task for a long peiod, the crystalline lens tend to over-focusing and can result in myopia. Therefore, maintain HARMON distance is a must in order to do avoid near vision task syndrome.(see picture no. 3 above)
b) Maintain good posture
Maintain good posture also is included in visual hygiene. It is important especially for those who are under VDUs condition. The poor posture will cause the neck and back aches. The proper natural posture is play a role to give maximum air to breath and also the other organ to be functionally well. Maximum oxygen that archieve to the eye is also important in order to give maximum load of near vision work. Therefore, the poor posture will give the effect on breathing and it also indirectly affected the eye function. The eye will suffer a lot of work with deprivation of oxygen supply. Despite this, the eyes will get tired easily due to this factor.(see picture 1 & 2 above)
Tilt the visual task position
When using the computer, adjust the angle of the computer monitor screen paralel with your surface and placed the computer on the flat desk. The comfortable distance is between 18” to 24” from the monitor screen to you and adjust the agle is 20° from the desk. It can relieve the stress of the body due to the poor posture and also changing of the focusing effort. It can reduce eyestrain and the eye not easily got tired. It is because the screen also must be lowered from the shoulder level of yours or slightly just below the eye level. For the children, they must obtain a desk and chair that appropriate for them. Parents should not take it as granted to use dining table for study table. It is not simply as that.
d) Proper distance for viewing
Children who are spend most of the time in front of the television, parents must be beware of their distance. They should sit 6 to 8 feet from the television in order to reduce the eyestrain. The children commonly like to see the television much closer rather than adult because of their tactile senses. Therefore, expert always advise that parent must wisely convert their children passive television viewing time to the active task such as outdoor activity, jogging, playing badminton and also on.
It is a preventive step in order to reduce the eyestrain due to loaded of the near work for a long time. The much time children spend in front of the television will increase the eye accommodation ability, and because of that reason, more children will end up with the accommodation spasm. The condition is become worse when the children is expose the television in the dim illumination
e) Good lighting
If you suffer for the illness and need to do near vision task, do not supine or use your stomach to support your near task material. You should avoid the too close near vision task. It will reduced your visual stamina. If you lies down, the brain will set the mind to tell your eyes to be divergence condition. But, if you are doing near vision task during supine, the eye will converge and accommodate. The eyes easily get eyestrain and in become fatigue. It is because the innervation of the nerve will forced out each other to bring the eye converge eventhough it actually set up in divergence condition. There is how your eye only can maintain their visual stamina only for a few minutes compare when you are reading at the good upright standing.
g) Writing habit
Parents and teachers should educate children the right way to writing. They should encourage children to hold pen or pencil an inch from the tip of the pen or pencil. It is because, the way how their writing habit may induce the head tilt and also ergonomic. The children tend to tilt their head or move their body to the one side in order to see the tip of their pen. The strain of the neck and back muscle will interrupt the focusing ability and especially will interrupt their study.
h) Peripheral awareness
The eyes should be trained for not to be focused only at one object. The eyes must also be trained to stimulate with the peripheral awareness. When the eye are well-trained according to the peripheral awareness, it actually easily become relax because it has good sensitivity of the peripheral vision even though it is in focusing near work load. The eye will easily turn the stimulus at periphery and therefore the focusing power also change. It also will indirectly relax the accommodation of the eye.
i) Near vision task set-up
For those people who are in computer work station, they should arrange their computer position to avoid glare on the screen that can cause eyestrain. The glare might come from the external sunlight or internal lighting. The position of the computer must be out of direct sunlight or room light, but it is not necessary become inadequate light or under dim light.
j) Reading or sustained near work avoidance during car travelling
Expert always concerning about reading or sustained near work during car travelling. They believe that, instead of doing such activity like reading and playing video game in the car, they suggested that to see the scenery. In fact, the distance and greenery scenery is one of the condition to relax the accommodation of the eye.
Besides that, when the car is travelling, our cochlear in the aer will send the message to the brain that tell our eyes in relax condition and eye movement will follow the image passed by. But, if the eye are used for near vision task in travelling car, it will induced the other eye movement such as saccadic aye movemnet. The innervation of the nerve will force to each other and end up with the eyestrain.
k) Healthy lifestyle practice
Healthy lifestyle practice are include the eating lifestyle, regular exercise and also on. Nutritional diet especially Vitamin A is known as the essential vitamin for the eye. It can be taken by shallowed the Vitamin A supplement or it can be eaten freshly in your meal.
Regular body exercise especially your eyes also is a must. The body need some attention in order to work properly. So, regular eye examination and if needed, do the home or office therapy for healthy vision. The regular and proper eye exercise will increase the visual stamina and the vision can be improve.
As a conclusion, vision is an ample thing in the world. Our world demands more from our eyes than ever before. In our technological society we use our vision intently at work, home and play. As you age, your visual skills will either improve or deteriorate depending on the way you use your eyes.
By following the simple tips outlined above, we actually can prevent the onset of vision problems. We also will develop better visual abilities and see more comfortably. These suggestions lead us to seeing our world more easily, efficiently, stress free and beautifully. Therefore, the conciousness of these healthy visual lifestyle is important in order to minimize the stress and eyestrain of prolonged visual tasks and help keep your eyes from getting worse.