Eyesight and Computers
Do Computers affect your eyesight?
The second more common cause that leads young, healthy people to the ophthalmologist are the problems caused using computers. People who spend many hours a day in front of a computer, develop a condition called “asthenopia”, which means a difficulty to see, as well as a condition in the fingers and the arm muscles due to the repetitive movement of the fingers.
In general, the effect from computers on the eyes and vision is currently being studied, even though no serious permanent damage has been observed.
Over 50% of computer users suffer from eye fatigue, headaches and blurry vision. These symptoms often affect a person’s overall health, resulting in a general feeling of fatigue which may even lead to decreased performance in the workplace.
Furthermore, in rare cases, evidence suggests that people who work many hours a day on a computer are more susceptible to glaucoma.
How do Computers affect your vision?
When you stare at a computer screen you focus on a single point and lose sense of depth and stereopsis. Furthermore, eye convergence (the two eyes come closer together when looking at something that is at close distance) is always active, while blinking frequency is reduced. This is completely different from reading a printed page, because computer screens, and especially CRT screens, do not produce a continuous image but rather flickering frame by frame image which is constructed into a continuous image by our brain. After many hours in front of a computer the cones, i.e. the cells that are used by the eye for the perception of color, are constantly working very hard and, as a result, the image that is created by the cones stays in our brain, even though the image on the screen has changed. This is called an “after effect” or McCollough effect and in some occasions, even color perception is reversed.
One of the questions that concern us about computer use is to what extent are we submitted to ultraviolet radiation or radiation in general and if this could lead to the development of cataract. We should note that current evidence suggests that the radiation we are exposed to, with regards to ultraviolet radiation from the computer screen, is less that the radiation we are exposed to from a fluorescent lamp and consequently there are no harmful effects for the eye, nor is there any indication that this exposure could lead to cataract.
Ophthalmologic symptoms caused due to Computer use
- Headache during and after PC use
- Pain between the eyes
- Blurred vision
- Dry and/or irritated eyes
- Slow refocusing during screen use
- After long hours of PC use there is difficulty in viewing distant objects
- Occasional double vision
- Poor color perception
General physical symptoms caused due to Computer use
- Neck and/or shoulder pain
- Pain in hands and wrists
- Reduced work performance, frequent mistakes, fatigue
The computer screen should be at a slightly lower level that the level of the eyes and the keyboard should be in such a position that the lower part of the arms and the wrists is parallel to the ground. Furthermore, the hands and the thighs must also be parallel to the ground. The chair needs to have adjustable parts so that it can be adjusted to each user’s individual needs.
Brightness and contrast need to be adjusted to the desired setting, so that the user feels comfortable and the eyes do not get tired. Usually, room lights need to be three times brighter intense than that of the screen, while a screen filter should also be used. It is important to work on a large screen to avoid having to put in a great effort to read or write, while also using a font size that is comfortable for you. Make sure that light from a window or other light sources does not reflect on the screen. Finally, the computer screen should obviously be regularly cleaned.
If computer users experience a minor refractive anomaly, such as myopia, hyperopia or astigmatism, its correction with the use of glasses or contact lenses could help them use computers more easily.
Furthermore, xerophthalmia, which may be caused by prolonged use of computers and a reduced rate of blinking, can be treated with artificial tears as well as by properly moisturizing the work place area.
Finally, the most important measure for preventing unwanted eye symptoms is taking short and frequent 2-3 minute breaks every 15-20 minutes of work or 5 minutes every half an hour or 10 minutes every hour.
Problems from excessive computer use during childhood
In Europe, the U.S.A. and in the last few years in Greece as well, children spend 1-3 hours a day in front of a computer screen either for school-related activities or for entertainment. Quite often, it is the parents who encourage their children to use the computer, even from the very early age of two or three years. A very large percentage of school-age children have access to a computer either at school or at home.
Many pediatric-ophthalmologists believe that the excessive use of a computer during childhood could lead to myopia, while others refer to studies which have shown that computers negatively impact children’s vision.
More specifically, various studies show that: A) 25% of children need corrective glasses to comfortably and safely work on the computer while at home or at school, b) the percentage of children with early stages of myopia has increased from 12% in 1995 to 25% today, and c) the percentage of children between the ages of 7-9 with myopia has tripled during the last three years, reaching 34%.
Up to 20 years ago, most children used to play outside and their distant vision was more important. Today, however, most children spend their time in front of a computer both at home and at school, leading to problems that a few years ago were not known. When using a computer, a child’s optic system is more focused than during any other activity. Computer use requires high levels of skill from young children’s eyes, even though their optic system has not yet fully developed, which is why once the child has grown, it can effectively manage the stress and pressure caused by computer use.
According to the American Academy of Optometry, the consequences from computer use in childhood include the following:
Generally, children have a very limited degree of self-protection. They may spend many hours in front of a computer with few to no breaks, which could lead to focusing and attention problems.
Furthermore, children are very adaptive as they believe that what they see and the form in which they see things is perfectly normal even if their vision is impaired; therefore, parents must have a decisive role in the amount of time their children spend in front of the computer.
Children are smaller than adults. Most of the time, the work space in front of the computer is designed to accommodate adults, which could change the children’s optic angle (anyone who uses a computer should tilt their screens slightly, at a 15⁰ angle). Finally, children may suffer from neck, shoulder or back pains because of the difficulty in reaching the keyboard or touching their feet on the ground.
Advice to avoid problems from computer use in childhood
Many pediatric ophthalmologists claim that children who use a computer before their optic system has fully developed face a condition known as “computer vision syndrome”. You can follow the following tips to protect your children from this condition:
Before going to school, children need to be submitted to a complete eye evaluation, including both far and near sight.
The work space in front of a computer must be adjusted to the size of a child and not to that of an adult.
The recommended distance between the computer screen and the eyes is 50-60 centimeters, because if children look at the computer screen from a closer distance, they run the risk of hurting their eyes due to the excessive visual adjustment.
Parents should always monitor the time children spend in front of a computer and make sure that they take breaks, so that their visual and musculoskeletal systems can rest.
In conclusion, parents and teachers need to be able to identify possible problems including: Frequent eye rubbing, head leaning or other unusual body stances, and finally complaints for tired eyes or blurry vision and immediately schedule an appointment with the ophthalmologist.
Finally, keep in mind: Your ophthalmologist is the best source for responsible information on issues that are related to the health of your eyes. Under no circumstances is the information available on our website intended to replace your doctor. Always contact your doctor for information.