COMPUTER VISION SYNDROME – WATCH YOUR BACK!
Studies have indicated that 70 to 90% of people who use computers extensively, whether for work or play, have one or more symptoms of computer vision syndrome. The effects of prolonged computer use are not just vision-related. Complaints include neurological symptoms like chronic headaches and musculoskeletal problems like neck and back pain. Akinbinu and Mashalla1 cited four studies demonstrating that use of a computer for even three hours a day is likely to result in eye symptoms, low back pain, tension headache and psychosocial stress. Still, the most common computer-related complaints involve the eyes, which can develop blurred or double vision, as well as burning, itching, dryness and redness, all of which can interfere with work performance.
FOCUS AND GLARE
Unlike words printed on a page that have sharply defined edges, electronic characters, made up of pixels, have blurred edges, making it more difficult for eyes to maintain focus. Unconsciously, the eyes repeatedly attempt to rest by shifting their focus to an area behind the screen, and this constant switch between screen and relaxation point creates eyestrain and fatigue. Instead of a normal blink rate of 17 or more per minute, working on a computer often reduces the rate to only about 12 to 15 blinks. This can result in dry, irritated eyes.
Inadequate lighting and glare are another problem. Contrast is critical, best achieved with black writing on a white screen, brighter than the ambient light. Bright overhead light and streaming daylight force the eyes to strain to see what is on the screen. You might need to reposition your desk, use a dimmer switch on overhead lights, or lower window shades to keep out sunlight. In addition, using a flat screen with an antiglare cover, and wearing glare-reducing or tinted lenses can help to minimise glare.
Be sure to use a font size best suited to your visual acuity, and have your eyes examined regularly – at least once a year – to be sure your prescription is up to date. This is especially important for people older than 40 and for children who are heavy users of computers because visual acuity can change with age. Make sure that your monitor has a high-resolution display that provides sharper type and crisper images, and clean the monitor often with an antistatic dust cloth. If you already have symptoms of computer vision syndrome, there are ways to reduce or eliminate them. Ophthalmologists suggest adhering to the ‘20-20-20’ rule: Every 20 minutes, take a 20-second break and look at something 20 feet away.
People taking tear-suppressing medications for a chronic illness might ask their doctors about trying an equally effective substitute that lacks this debilitating side effect. If blepharitis is a chronic problem, wet a washcloth with hot water and apply warm compresses to the eyes every morning. This can be the cheapest and most effective remedy.
GENES OR ENVIRONMENT?
The rapid increase in nearsightedness appears to be due to a characteristic of modern life: more and more time spent indoors under artificial lights. Our genes were originally selected to succeed in a very different world from the one we live in today. Long ago, we spent most of our waking hours in the sun.
Should we say that the sun is the best optometrist? In the early 1980s, 35% of Africans were nearsighted; three decades later, the rate had risen to 56%, and similar increases have occurred worldwide. The trait is inherited, so you might wonder why our myopic ancestors weren’t just removed from the gene pool long ago, when they blundered into a hungry lion or off a cliff. But although genes do influence our fates, they are not the only factors at play.
Researchers suspect that bright outdoor light helps children’s developing eyes maintain the correct distance between the lens and the retina, which keeps vision in focus. Dim indoor lighting doesn’t seem to provide the same kind of feedback. As a result, when children spend too many hours inside, their eyes fail to develop correctly and the distance between the lens and retina becomes too long, causing faraway objects to look blurred.
Sports-related eye injuries can be quite serious. I suggest that anyone involved with youth sports should be vigilant about protecting young people’s eyes, perhaps by stocking up on wraparound glasses. If you’re dealing with projectiles or fast-moving objects such as a ballistic paint blob or a baseball, protective eyewear is definitely worthwhile. Wraparound glasses with shatterproof lenses can keep out a lot of undesirable objects including fingers, debris and misdirected curveballs.
EAT WELL FOR EYE HEALTH
Natural foods provide a preventive remedy. Our eyes benefit from beta-carotene. When taken in combination with zinc and vitamins C and E, beta-carotene may reduce the progression of age-related macular degeneration (AMD). This can be sourced from carrots, sweet potatoes, spinach, kale, and butternut squash. Bioflavonoids may also protect against cataracts and AMD: tea, red wine, citrus fruits, bilberries, blueberries, cherries, legumes, and soya products are good sources. Lutein and zeaxanthin, easily absorbed from spinach, kale, turnip greens, collard greens, and squash, may be of use to prevent cataracts and AMD.
Omega-3 fatty acids are of paramount importance: eat cold-water fish such as salmon, mackerel and herring, freshly ground flaxseeds and walnuts to prevent AMD and dry eyes. Vitamin A-rich foods like beef or chicken liver, eggs, butter and milk are of value in protecting against night blindness and dry eyes. Vitamin C sources like sweet peppers (red or green), kale, strawberries, broccoli, oranges and cantaloupe may reduce the risk of cataracts and AMD.
Vitamin D foods like salmon, sardines, mackerel, milk, and orange juice fortified with vitamin D are recommended for reducing the risk of macular degeneration. Remember the best source of vitamin D is exposure to sunlight. Just a few minutes of exposure to sunlight each day (without sunscreen) will ensure your body is producing adequate amounts of vitamin D.
- Vitamin E from almonds, sunflower seeds, and hazelnuts, when combined with carotenoids and vitamin C, may further reduce the risk of advanced AMD.
- Zinc from oysters, beef, crab and turkey (dark meat) helps vitamin A reduce the risk of night blindness, and may play a role in reducing the risk of advanced AMD.
- In general, it's best to obtain most nutrients through a healthy diet, including at least two servings of fish per week and plenty of colourful fruits and green vegetables.
1. Akinbinu TR, Mashalla YJ. Impact of computer technology on health: Computer Vision Syndrome (CVS). Medical Practice and Reviews. 2014;5(3):20-30.