Posture and Vision (3)
Visual Hygiene and Near Work Visual Habits
Some tips in brief:
- Do all near point activity at HARMON distance or slightly further.
- For reading, writing, and other near vision tasks it is important that the object being viewed be kept adequately far from the eyes. The working distance should be at least 40 cm (sixteen inches) for adults and older children, and at least 30-33 cm (twelve to thirteen inches) for younger children. When the viewing distance is shorter, the demands upon the focusing system become increased out of proportion to the few inches involved. This increases demand can lead to severe stress and strain.
- Therefore, maintaining an adequately long working distance is the foundation of good visual hygiene and depends upon good relaxed posture and proper lighting. 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.
- When reading, occasionally look off at a specific distant object and let its details come into focus. Maintain awareness of other objects and details surrounding it. Do this at least after two or three pages.
- Desk work should be performed at an appropriately sized desk and on a surface inclined at an angle of 20 degrees. 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. 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 2,5 to 3 meters 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.
Inspired from: http://www.gallopintovision.com/visual_hygiene.htm
In summary:
The essential elements of visual hygiene tips are:
- posture
- distance
- furniture
- lighting
- relaxation (breaks)
Posture: Sit with a straight back, with head straight, aligned for the task, neither tilted excessively forward nor backward, nor tilted to either side. This position should be maintained throughout all near activities. Avoid reading in bed or lying down. No lying on the stomach, no slouching, no curling up or other asymmetric positions.
Distance: for reading, writing, drawing, hand-held video game, etc.: everything must be done at forearm’s length. For desktop computer, the screen should be placed at arm’s length (fingers must just barely touch the screen). For a laptop, a working distance of 50 to 60 cm is recommended.
For television: At least 2 to 3 meters, with head and back straight.
Furniture:
If children or shorter people are working on a regular table (ex kitchen table), they should sit on a higher stool or a cushion. Otherwise, use a smaller table adjusted for their height.
Lighting: Use general overall lighting in the room and add supplemental lighting as needed for the task. Make sure there is even lighting across your work. Never work in the dark.
Taking breaks: a 10 minute break after a 60 minute period is beneficial.
Note: This ends all that I had to say about myopia and the control of this condition. I hope these texts have made you more aware about myopia and that you will be able to help your child in the prevention or control of his or her myopia.