When to look away from your screen

Sitting hunched over while staring at a computer screen isn’t great for your spine or your eyes.

The eyes are not built for what a typical workday looks like, says Dr Paul Casey, a ophthalmologist. Staring for hours at a screen centimetres away is a huge strain on the eyes.

Looking away from your computer from time to time isn’t enough, though. Simply switching your focus, such as looking 5 metres away a few times an hour, can help reduce strain, Casey said.

Think of the muscle movement required to zero in. ‘‘Try to focus on something 10cm from your eye, and you’ll feel . . . there’s real work going on there,’’ he said.

When your focus is farther away, the eyes relax, and the muscles aren’t working as hard.

When working for extended periods of time at a computer, the ciliary muscle needs to contract to focus, he said.

‘‘That muscle can get cramped, and it can actually become difficult to uncramp it,’’ Casey said. ‘‘The eyes can just feel real tired and achy.’’ He recommends an exercise. Every 20 minutes or so, look about 5m or more away from your desk, and let your eyes linger for about 20 seconds.

Find something that can be a target for your eyes, and that will break the spasm – or even prevent it, Casey said.

‘‘That’s long enough to take a break,’’ he said. ‘‘You can’t just look at your coffee cup – that’s not far enough away.’’