(Kim Komando) You know the blurry vision and dry eyes you get when you've been staring at a computer, smartphone, TV or other screen for a few hours? According to researchers at a group called the Vision Council, that's not a good thing. And to really drive the point home, it's dubbed the problem "digital eye strain."

The Vision Council defines digital eye strain as "the temporary discomfort that follows from two or more hours of digital device use." Common symptoms include "red, dry or irritated eyes, blurred vision, eye fatigue, back, neck and shoulder pain, and headaches."

 According to the Vision Council's latest survey, 70 percent of tech users experience digital eye strain regularly. While it's suspiciously convenient that a group representing eye companies is bringing this up, it's no secret that technology causes some unique health problems - and not just for your eyes.

In addition to digital eye strain, some other tech health problems are repetitive-stress injury, shoulder tension, back and neck pain, and increased risk of cancer, heart disease and obesity. Some studies show that extended computer use can shave 10-15 years off of your life!

Before I continue, just let me remind you that I'm not a doctor. If you're experiencing chronic pain or other odd symptoms, consult a professional for a formal diagnosis.

In the end, however, almost every tech health problem comes down to two things: Insufficient breaks and poor posture.

Many doctors recommend that every 20 minutes you look at an object 20 feet away for 20 seconds. This gives your eyes a chance to focus at a different distance, and get away from the bright screen backlight.

Speaking of backlights, grab a program like F.lux to match your monitor tint to the time of day. It can decrease eye strain and improve your sleep.

Every hour or so, stand up and do some quick stretches or walk around your house. Programs like BreakTaker and Workrave can help remind you when it's time to take breaks.

You should strive for about 30 minutes of daily exercise, too. Walking the dog or doing some yard work is enough for most people. This improves your circulation after sitting for hours on end.

Posture is just as important. Have you heard about "iPosture"? This refers to the way most people use phones and tablets: head down and shoulders hunched over. It can lead to back and neck strain, in addition to the digital eye strain from staring at a small screen.

In fact, studies show that teens and young adults are increasingly having medical problems from standing or sitting this way for long periods. Not to mention thumb injuries from continual texting.

For smartphones and tablets, it's better to sit upright and keep the gadget just below eye level. Again, taking regular breaks for your eyes and hands is important.

Bring the screen brightness down as far as possible and then increase it gradually to find a point where it's comfortably visible. Not only will this reduce eye strain from too-bright backlights, it makes your battery last longer. Learn how to adjust the brightness and more in this essential tip on improving gadget battery life.

Good posture at a computer is just as important. Start with a good chair that offers lumbar support, and sit at a 110-135 degree angle.

Adjust your seat so that your feet touch the floor and your legs rest at about a 90 degree angle. Your knees should be even with or a little lower than your hips. Your forearms and wrists should rest comfortably on your desk or work table, with your elbows at a 90-degree angle.

Many people like the gel-filled wrist rest for keyboards and mouse pads. While it seems like it would help to rest your wrists on these while working, it doesn't. When you're typing and moving your mouse, you want to keep your wrists in the air, level with your hand.

This allows your hand and arm to move together naturally. Otherwise, you end up stretching your fingers and moving your hands into odd angles while hitting keys and moving the mouse.

Another common problem is that too many people set their monitors too low. This causes them to slouch, or scrunch, which puts strain on the neck and shoulders.

Then there's what's on the screen. When you're browsing the Web, for example, you might notice the fonts and images on your screen are too small. This can cause you to lean forward or strain your eyes trying to read.

In any Windows browser, and many programs, use the keyboard shortcut CTRL + + (plus) to zoom in and CTRL + - (minus) to zoom out. CTRL + 0 (zero) brings the zoom back to 100 percent.