Do your eyes make your body sway?

A large pruple and cream coloured vertical exhibit, that has a series of vertical timber pieces hung between two large panels.

Your sense of balance is strongly influenced by what you see.

How it works

Stand on one leg, up close to a swaying board printed with black and white stripes. Can you keep your balance?

Things to try or ask around the exhibit

  • How does your body move when you're watching the striped board?
  • Try closing your eyes and see if it's easier or harder to keep your balance.

Background

To stay upright, your brain combines signals from (most importantly) your vision, as well as your vestibular system (inner ear fluid canals), and stretch receptors in your joints and muscles (proprioceptors). If you stand still with your eyes closed, you sway 20–70% more than usual, because you are missing vital visual information about how your body is positioned in space.

When you see your surroundings move, your environment is likely to be moving too (just like when you’re riding on an escalator). At other times, if you see your surroundings move, it means that you’re falling over. To prevent yourself from toppling over, your body often adjusts how you’re standing.

Finding the science in your world

When you play a computer game, or watch a movie, you may get a strong sense of movement, even though you’re sitting still.

If you’re standing still on a footpath watching passing traffic (particularly large buses), you may start to feel a little unbalanced. Older people are especially prone to falling over in busy traffic, because people lose their sense of sight and balance as they age.