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Friday 5 October 2012

Headache? Stiff Neck? ... Computer Vision Syndrome



Headache? Stiff Neck? You May Have Computer Vision Syndrome (The Cure Is Simple)


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Are you prone to headaches or a stiff neck—and you can’t figure out why? The surprising cause may be computer vision syndrome. Here’s what you need to know...

DISTANCE IS EVERYTHING


Computer monitors usually are positioned between 20 and 26 inches from the eyes. Eye-care professionals call this the intermediate zone of vision.

Generally, children and young adults can see clearly and comfortably at this distance without glasses (if they have perfect vision) or with their general-purpose glasses or contacts (if they need prescription eyewear for nearsightedness, farsightedness and/or astigmatism).

Seeing clearly at the intermediate zone becomes more difficult once we reach our 40s, due to a normal age-related loss of focusing power and flexibility called presbyopia. This is especially true once it becomes apparent that you need multifocal lenses—bifocals, trifocals or progressive lenses—or reading glasses.

Multifocal lenses for general-purpose use may not have a large enough intermediate-viewing zone for computer use, or the zone might be positioned too high or too low in the lens.

And reading glasses that may be perfect for reading a book or magazine may be too powerful for comfortable computer vision.

The end result: You may find yourself with less-than-clear vision while using a computer that leads to squinting, eyestrain and headaches, or adopting bad postures—leaning forward in your chair, craning your neck or hunching your shoulders—causing neck, shoulder and back pain. This combination of stress-related symptoms is called computer vision syndrome.

WHICH GLASSES?


How can you avoid the discomfort, fatigue and lost productivity associated with computer vision syndrome? For many people, the answer is specially prescribed computer glasses.

Though computer vision syndrome can affect people of any age, computer glasses tend to be most helpful for adults with presbyopia and younger adults who may not yet need multi-focal glasses or reading glasses but have symptoms of eyestrain during and after computer use.

To help your eye doctor determine the best prescription for your computer glasses, measure the distance from your eyes to your computer screen. Measure from the bridge of your nose to the middle of the screen—whether the screen is on your desk or balanced on your lap. Write down the measurement, and bring it with you to your eye exam.

Best choices...

Single-vision computer lenses work well for people who keep the monitor or laptop screen at a consistent distance—on a desk, balanced on the lap, etc.

Your eye doctor will prescribe lenses that match that distance. It doesn’t matter if you also use reading/distance glasses, since you will use the computer glasses only when you’re working on the computer. Single-vision lenses provide a larger field of view (the total area that you can see clearly through the glasses) than other designs. They also are less expensive than multifocal computer lenses.

Multifocal computer lenses. Multi-focal is the general term for bifocals, trifocals and progressive lenses (which don’t have the lines that you can see on bifocals and trifocals).

Because they have different viewing zones for intermediate and near vision, multifocal computer lenses allow you to use one pair of glasses for computer work, reading small print and using your phone and other handheld devices.

You might prefer a multifocal lens if you frequently move your eyes back and forth from your computer screen to documents on your desk. Someone who does data entry, for example, might find multifocal computer glasses more comfortable than single-vision lenses. Multifocal lenses also might enable you to see both your computer screen and your keyboard more clearly than single-vision lenses.

Some computer lenses are for intermediate and near vision only, while others include a small “distance” zone in the top portion of the lens for looking at objects or people several feet away or even across the room. The distance zone of a computer multifocal (if one is present) is limited in size, so never wear multifocal computer glasses for driving or other tasks that require a clear, wide field of view in the distance.

Important: If you decide to get multi-focal lenses, take measurements of the distance from your eyes to your desk surface, as well as from your eyes to your computer screen. The main portion of the lenses will be adjusted for the computer, and the bottom portion will have added magnification for closer objects.

Antireflective (AR) coating. This coating eliminates most of the reflections of overhead lighting that appear on both the front and back surfaces of eyeglass lenses. This improves the brightness and clarity of the computer screen and reduces eye fatigue. Also helpful: A slight tint on the lenses to block the “blue” light emitted from computer screens and overhead lighting that increases glare and eyestrain.

EYE CARE


Wearing glasses might not eliminate all discomfort if you spend long hours in front of the screen. Also important...

The 20-20-20 rule. Take at least a 20-second break for every 20 minutes that you’re in front of the computer... and let your eyes completely relax by looking at something that’s at least 20 feet away—this relaxes the focusing muscle inside the eye, reducing the risk of eyestrain and fatigue.

Blink. Research has shown that during normal, face-to-face conversations, people tend to blink an average of 15 to 16 times per minute. During computer use, this drops to an average of just over five blinks per minute. This greatly increases the risk for eye dryness and irritation.

Blinking spreads a fresh lubricating layer of tears across the surface of your eyes to improve comfort and the clarity of your vision. Remind yourself to blink normally—or take a “blink” break every minute or two. And blink fully. Some people blink only partially when they work on a computer.

Remove your contacts. Because prolonged computer use increases your risk for dry eyes, it also frequently causes contact lens discomfort. And when your contacts dry out, you’re more likely to experience blurred vision, eyestrain and headaches. Contacts are fine for brief periods of computer use, but if you know you’re going to be staring at a screen for hours, remove your contacts and wear glasses or computer glasses instead.

Also helpful: Keep artificial tears at your desk, and apply a drop in each eye when you first notice dryness, fatigue or irritation. Use preservative-free artificial tears—preservatives can cause increased eye sensitivity and irritation with prolonged use.

Source: Gary Heiting, OD, who worked as a clinical optometrist and optical-industry consultant for more than 25 years. Based in Stillwater, Minnesota, he now is senior editor at AllAboutVision.com, a Web site that provides consumers with independent, doctor-reviewed information about eye health, eye care and vision-correction options.

Listing Details

Publication
Bottom Line Personal
Original publication date
September 1, 2012