COMPUTER VISION

SYNDROME

Dr. S. Sanjay, MS, DNB (Oph) - Associate Consultant.

Rajan Eye Care Hospital

Computers have become indispensable in the workplace. The professionals spend increasing amount of time sitting at their computer workstations and they take less and less breaks running the risk of being exposed to working at high speed aligning to tight deadlines. This is the backdrop of COMPUTER VISION SYNDROME, which is defined as that complex of eye and vision problems experienced during or related to computer use. The computer population is 20 millions plus and 80% of them (16 Million) have discomfort due to CVS. The prevalence of eye symptoms among computer users range from 25.93% as reported by various investigators. The combination of fixed and constrained body postures; work overload and unsuitable workstation can lead to health problems. The most common complaints among computer users are aches and pains in the shoulder, forearm, wrist, hand, back, neck, and eyestrain.

Repetitive Strain Injury (RSI) is a blanket term that is used to describe many different types of work-related disorders and injuries to upper limbs as a result of muscular overload. This is usually caused by repetitive movements and/or overuse of specific muscle groups (categorized as static load) especially if the joints adopt extreme positions. RSI is not a new disease and also affects people who do not work at a keyboard.

This article is intended to prevent health problems among computer users. Clearly a large percentage of Computer operators experience eye related symptoms and subsequently seek eye-care. Computer Vision Syndrome can include, Headaches, Neck aches, Backaches, Eyestrain, and Blurred vision, Dry or irritated eyes, Light Sensitivity, Double vision etc. These symptoms are often a result of a combination of three factors - Workplace conditions, Working habits, and Visual conditions.

The Computer Workstation:

The Chair - When you sit, the weight on your lower back is one and a half to two times bigger than what you stand. A good chair must accommodate your body sizes and must be adjustable in the following areas.

Height of the Seat - When your feet rest comfortably on the floor, a 90-degree angle between upper and lower legs is desirable in this position, your upper legs are virtually horizontal.

Depth of the Seat - The clearance between the front edge of the seat and the back of your knee must fit a clenched fist.

Backrest - The backrest must support the area from the upper ridge of the pelvis to the shoulder blades. The curve in the backrest must support the hollow in your lower back. An adjustable tilt is desirable.

The Primary factors that determine discomfort for computers are; nature of the task, length of time spent at the computer and reduced rate of blinking and lack of coordination between the design of the workstations and the design of the glasses or contact lenses used for the task. The average rate of blinking is 12 to 15 times per minute. This is frequently reduced during intensive tasks leading to visual fatigue and dry eyes. Therefore, reading from a screen reduces blinking, which in turn leads to discomfort.

Some examples of user discomforts are; intense tasks such as games, tasks with few breaks from the screen, tasks which require constant looking from copy to screen such as data entry. Detailed tasks such as desk top publishing or Computer Assisted Design (CAD), Eye level placement of screens that causes eyes to be wide open causing faster drying, Eye level screens that are too high for most bifocal wearers unless they have specially designed glasses for this task and glasses that exacerbate the restriction of movement which is a consequence of most computer tasks causing neck, shoulder and arms problems.

Lighting:

Ideal lighting conditions should be between 180-460 lux levels. Good lighting levels can significantly help reduce discomfort due to glare. Light leaving the fixture can be directed so that it goes straight down and not into the eyes of the room occupants. This is most commonly accomplished with the louvers in the luminaries or fixture. An even better solution is indirect lighting in which the light is bounced off the ceiling - resulting in a large low luminance source of light for the room. Another efficient way to eliminate the brightness of overhead fixtures is the use of a Visor. A person can wear it for a day or two as a test to determine the extent to which the light problems activate e discomfort at the end of the day.

To minimize eye discomfort a computer user can; place the screen further away since eye strain tends to increase as tasks are closer - 20 to 28 in inches from his eyes; design the workstation to place the screen at least a few inches below eye level and eliminate reflections from the screen; do not have the screen excessively bright; keeping the monitor clean; have moderate background ambient illumination with supplemental task lighting for hard copy documents - ideally the illumination from the screen should closely match the light reflected from the document; use a copy holder to place documents so that they are at the same distance from the users eyes as the monitor; place hard copies in a plane parallel to the plane of the user’s head to minimize reflections, maximize legibility of print and keep the whole document the same distance from the users eyes; have properly designed lenses for the task; use supplementary eye lubricants as indicated, minimize glass glare on your computer by turning your monitor away from the window, reducing strong overhead light, balancing overhead and window light with a desk lamp and using an antiglare screen; give your eyes a break by looking away frequently from your monitor for a few seconds.

Working at the computer is not harmful to the eyes. But have your eyes examined if you are a first time keyboard operator and experience eye problems. Consult your eye care professional regularly to update your prescription.

Do's and Don’ts in fire fighting

Learn not to burn. Do's

Ø Contact local fire officer to learn basics of First Aid fire fighting.
Ø Give way to fire engine.
Ø Help firemen to help you out
Ø Faulty electrical appliances should be repaired/replaced immediately.
Ø Switch off the electric supply of the fire affected areas.
Ø Switch off appliances after use and remove the plug from the socket.
Ø Keep matches, lighters and crackers away from children.
Ø Keep LPG stoves on raised platform - never on the floor.
Ø Turn off the cylinder valve and burner knob of the gas stove after cooking.
Ø In case of burn injuries due to fire, pour water over burn till pain subsides.

Don’ts

Ø Don’t block escape routes.
Ø Don’t use Non ISI equipment/ appliances.
Ø Don’t compromise with money and quality of safety equipment.
Ø Don’t dispose off lighted cigarette ends carelessly.
Ø Don’t plug too many electrical appliances in one socket.
Ø Never have temporary or naked joints on wiring.
Ø Don’t lay wires under carpets, mats, or doorways.
Ø Never place oil lamps, agarbattis or candles on the floor or near combustible material. •Don’t ear loose, flowing clothes while cooking. Avoid synthetic clothing.
Ø Never reach for any article over a fire.
Ø Hay stack should not be built up near the railway lines or roads.
Ø Don’t park your cars/trucks close to fire hydrants/underground static water tank.
Ø Don’t misuse First Aid fire fighting equipment.Don’t use lifts in case of fire..