The visual process can be protected by simple precautions such as proper lenses, posture, lighting, ergonomics and working distance. Some pointers are provided.
There is ample evidence that conditions which lead to muscle tension and place undue stress on the visual system will, over a period of time, lead to visual problems such as nearsightedness and astigmatism, and other disorders such as focusing and binocular coordination problems like strabismus. Many authorities blame our culture’s emphasis, for both children and adults, upon prolonged near vision tasks (such as reading, computers and other hand-held devices) for an increase in visual problems.
We certainly cannot eliminate those tasks that need to be done, and may even be pleasurable. They can be carried out in a manner that imposes minimal stress on the visual system.
These suggestions, if followed, may result in easier and more productive study and desk work and will have value in preventing or retarding the development of visual problems.
- Proper lenses can make all the difference in the world. Most doctors remain unaware of the importance of proper near lenses for people of all ages. The proper lenses can reduce and prevent stress and keep the visual system in optimal working order throughout our lives.
- It is important for reading, writing, and other near vision tasks that the object being viewed be kept adequately far from the eyes. The working distance should be at least sixteen inches for adults and older children, and at least twelve to thirteen inches for younger children. When the viewing distance is shorter, the demand upon the focusing and eye teaming systems becomes increased out of proportion to the few inches involved. This increased demand can lead to severe stress and strain. Therefore, maintaining an appropriate working distance is the foundation of good visual hygiene. Good balanced, relaxed posture and proper lighting are also important. Reading and writing while lying down, reading in bed, and other inappropriate postures tend to result in shortened viewing distances. Insufficient lighting also causes one to hold reading material inappropriately close in order to see it.
- Desk work should be performed at an appropriately sized desk and on a surface inclined at an angle of 20o. The chair should be of such size to allow the feet to rest comfortably on the floor. The buttocks should be flat and tucked fully to the back of the seat. Kitchen or dining room tables were not designed for studying or writing. They are usually too high and inappropriate for use by a child. It is desirable to read while seated erect in a comfortable chair. Tilt the book up about 20o. Read in bed only when sitting upright – if at all.
- For proper lighting when reading in a chair, illuminate the entire area using overhead/full-room lighting. Next, have another light on your book – one that avoids bright reflection on the task.
- When performing any prolonged near work, take breaks if you begin to feel your neck, shoulder, or back muscles beginning to tighten.
- Don’t get “locked in” when doing close work. Read or study no longer than fifteen to thirty minutes without interruption. Look up at a distant object as you turn each page, and try to get the distant object clear before beginning to read the next page. Looking back and forth from distance to near while reading reduces the tendency of the focusing muscles to become cramped.
- Be aware of your general surroundings while reading or viewing TV. Do not place desks against walls. Do not sit any closer to TV than is necessary. A minimum viewing distance of six to eight feet is reasonable.
- Active outdoor play is an essential part of normal and healthy development. Play activities that require seeing beyond arm’s length should be encouraged.
- When walking outdoors, sight a distant object close to eye level and try to be aware of the path, where things to either side, and between you and the object at which you are looking and beyond.
- When riding in a car, look in the distance rather than close by.
- When ill, try not to read or view TV for very long periods of time, especially if you have a fever. Similarly, try to avoid close work when you are very tired. Listen to the radio, or music instead, or some other non-visual activity.
- The best prevention is regular, professional care. We will indicate how frequently your eyes and vision should be rechecked.
Obtained from the Gesell Institute of Human Development, New Haven, CT.
Contact Dr. Gallop for more information about behavioral optometry, vision therapy or your own visual hygiene questions.