Safe Work Practices > Video Display Terminals

Date Reviewed: February 21, 2023

Video Display Terminals

Employees who operate a Video Display Terminal (VDT) for more than 10 hours per week or more than 4 hours per day may be susceptible to certain medical problems. All employees in these conditions will be informed of the following health hazards and provided training in the following safe work practice guidelines to minimize any risk of musculoskeletal disorders.

Health hazards can include, but are not limited to, visual fatigue (eye strain, burning, tearing, or soreness of the eyes, blurred vision, and headaches), musculoskeletal discomfort (leg aches, back aches, neck stiffness, hand and arm weariness, shoulder aches), repetitive strain injuries (tendonitis, carpal tunnel syndrome). Employees should be aware of early warning signs of these medical problems. These signs may occur during or after work, particularly at night and may include numbness, pain, tingling, swelling, burning sensations or weakness in their hand, wrist, elbow, arm, neck, shoulders or back. If any of these signs occur, the employee is encouraged to keep a log or journal of the symptoms and report them to your Division Manager and your physician. The work place of any employee showing signs of a medical problem should be evaluated and changes made to make the workstation ergonomically functional.

To minimize the medical risks involved with VDT, the following safe work practice should be followed:

•The monitor should be supported on a stable surface and be able to be angled by the operator as desired. It should be situated in a position that minimizes glare and the screen height should be adjusted for the most comfort. This is usually looking downward at an angle of 20 – 50 degrees. Employees with bifocals may need the screen height considerably lower than employees without bifocals. The viewing distance should be set at the most comfortable distance. The monitor refresh rate should be set as high as possible to prevent flicker, and the font size should be large enough to be readable without eyestrain.

•The keyboard should be located to allow operation in a comfortable position, with upper arms hanging comfortably at your sides and your forearms and wrists approximately parallel to the floor while keying.

•The mouse or trackball should be easy to operate and have a comfortable fit in your hand. It should be located to allow use while working with your upper arms comfortably positioned at your sides and your forearms and wrists approximately parallel to the floor. If you are experiencing persistent health symptoms in your dominant hand, wrist, arm, elbow, shoulder or neck, you should attempt to use the mouse with the other hand. You should avoid using a keyboard or mouse with a bent wrist, and should not rest your wrist or palm on the edge of your desk of keyboard tray. Remove your hands from the mouse or keyboard and place them in your lap for a few seconds from time to time.

•If there are adverse health conditions as a result of extensive use of a keyboard, a palm/wrist support should be used. This support should be used to support the palm, not the wrist, and should only be used when pausing from keying, not while keying. This will minimize the risk of nerve damage from continual pressure on the palm. The forearms should also be supported when frequently using the mouse.

•The workstation should have adequate leg room, and a foot rest should be used if required.

•A suitable document holder should be used.

•If a substantial amount of work on a VDT is done while standing, a footrest of approximately 15 – 20 cm, or an anti-fatigue mat should be used.

•If a substantial amount of time is spent talking on the phone while working on a VDT, a telephone headset should be used.

•The desktop or work surface used for a VDT should have sufficient room for equipment and materials. If the desktop is also used for writing purposes, the writing surface height should be approximately equal to the height of your elbows when seated comfortably.

•Your chair should be able to maintain a comfortable position while working. It should have a good back support, a rounded front on the seat so as not to cause pressure points on the underside of the legs, a height and angle that allow the feet to rest comfortable on the floor, a non-slippery seat with a breathable fabric, a stable base, coasters appropriate for the floor surface and arm rests which do not interfere with placing the chair in a comfortable work position. In order to avoid nerve compression, avoid resting your elbows on hard chair arms or other hard surfaces for long periods of time.

•Workstations should be positioned at appropriate distances from heating and cooling vents. The vents should be shielded to prevent excessive air from blowing onto you.

•You should try to vary your work activity throughout the day, or do 5 minutes of non-similar work each hour. Take your 15 minute coffee break every 2 hours. This will go a long way to relieve body or eye fatigue.