We used to ask our children not to look at the TV or computer for long time, but now during the COVID lockout they need to sit for hours in front of the TV and computer to attend school lessons. Parents are genuinely concerned about how this prolonged viewing of the computer will affect the eyes and vision of their child.
Computer Vision Syndrome (CVS) is the term used to describe the condition commonly seen in persons working on computers for long hours. The symptoms of Computer Vision Syndrome involve not only the eyes but also the musculoskeletal system.
Eye problems consist of:
- Eye strain, Watering
- Irritation and Foreign body sensation
- Headaches or pain in and around eyes
- Blurred vision
Musculoskeletal problems consist of:
- Pain in the neck
- Pain in lower back
- Pain in the wrist
- Inability to concentrate after a while
- Disturbed sleep
Other Problems:
Uncorrected refractive errors are the single most important factors that trigger off this disorder. Hence even a small refractive error need correction. It is ideal to check your child's vision at five years of age. Thereafter it is prudent to check the eyes if the child complaints of headache, eyestrain or blurred vision.
The CVS can be reduced by adjusting the computer monitor as follows
- Sit farther away from your computer screen. A good rule is to be at least 25 inches, or roughly an arm’s length, away.
- Adjust the height of the chair to keep the upper edge of the monitor screen below the level of your eyes so that you do not have to extend your neck or keep your eyes wide open to see the screen.
- Background should be light & letters dark. Black letters on a white background are easiest to read and least strenuous on the eyes.
- Keep the font size at least two points larger than the size you can read easily. Prefer scrolling on the screen rather than zooming down to have every thing in one view.
- Dim your screen if it’s much brighter than the rest of the light in the area. You could also adjust the room lighting so the contrast is lessened.
- Keep your screens clean. Dirty screens with fingerprints and other debris can strain your eyes even more.
- Viewing distance should be comfortable. Place monitor in such a way that there is no reflection of light on the screen. The source of light should be on your sides to avoid reflection on the screen. If a bright source of light e.g. a window is directly in front of your eyes, the glare will be highly disturbing. Some people feel comfortable working in a dimly lit room. Maintaining absolutely essential brightness is necessary to avoid straining eyes.
- If you have to work for long hours, use support for the lower back. Position your key board, mouse and monitor in such a way that the body remains in a straight posture to see as well as handle these.
- The eyes are constantly moving and accommodating while working on computers. To rest your eyes follow a 20:20:20 rule. It means that every 20 minutes take a break for 20 seconds and get up to look at a distance more than 20 feet. This will rejuvenate your eyes and make working more comfortable
- Computer glasses make working on computers comfortable and are not needed otherwise, for distance or near vision correction. Computer glasses should ideally be UV protective and have a good quality anti-reflective coating to avoid the glare.
BLUE LIGHT
Blue colour has elicited a of of interest nowadays. Blue light is the visible light spectrum with the shortest wavelength and highest energy, and similar to ultraviolet rays. The short-wavelength, high-energy light rays on the blue end of the visible light spectrum scatter more easily than other visible light rays when they strike air and water molecules in the atmosphere. The higher degree of scattering of these rays makes the cloudless sky look blue. Our eye only lets less than one percent of UV radiation from the sun to reach the retina. On the other hand, virtually all visible blue light passes through the cornea and lens and reaches the retina. Many eye care providers are concerned that the added blue light exposure from computer screens, smartphones and other digital devices might increase a person's risk of macular degeneration later in life. More research is needed, though, to determine how much natural and man-made blue light is "too much blue light" for the retina.
Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. When you're looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual "noise" reduces contrast and can contribute to digital eye strain. Research has shown that lenses that block blue light with wavelengths less than 450 nm (blue-violet light) increase contrast significantly. Therefore, computer glasses with yellow-tinted lenses may increase comfort when you're viewing digital devices for extended periods of time.
White LEDs may actually emit more blue light than traditional light sources, even though the blue light might not be perceived by the user. This blue light is unlikely to pose a physical hazard to the retina. But it may stimulate the circadian clock (your internal biological clock) more than traditional light sources, keeping you awake, disrupting sleep, or having other effects on your circadian rhythm.
A lot of mobiles have got blue light filters and some spectacles lens come with blue light filter. Hence many parents enquire about effects of blue light. Blue light is of concern because it has more energy per photon of light than other colors in the visible spectrum, i.e. green or red light. Blue light, at high enough doses, is therefore more likely to cause damage when absorbed by various cells in our body. Current research shows that for normal use a person need not be too much concerned about blue light and it's effect on the eye.
DRY EYE
Tears are constantly secreted in our eyes to keep the front surface of the eye wet. This wetness of front surface is absolutely essential for clear and comfortable vision. If there is tear deficiency, it will cause dry eyes and lead to computer vision syndrome. At times of extreme concentration like studying on a computer, the blinking rate usually decreases. Humans normally blink around 15 times each minute. When staring at screens, this number decreases to a half or third that often. That can lead to dry, irritated, and tired eyes. Tears dry up faster leading to a to false dry eye state. Such cases can be helped by artificial tears, available as Eye Drops. One should also try and blink as normally as possible. A simple method is called the 20 20 20 rule.
Some research has shown that lack of outdoor activity and sunlight exposure may cause myopia or short sight. So it is prudent that children spend atleast one hour outside and get some exposure to sunlight.
Every 20 minutes take a break for 20 seconds by looking at an object more than 20 feet away. This gives rest to the eye muscles and helps replenish the tear film.
OUTDOOR ACTIVITY
Some research has shown that lack of outdoor activity and sunlight exposure may cause myopia or short sight. So it is prudent that children spend atleast one hour outside and get some exposure to sunlight.
