What happens when we blink our eyes
Ever wondered why we are not plunged into intermittent
darkness when we blink? Researchers in Singapore may have the answer. It is
because our brain works extra hard to stabilise our vision, without which our surroundings
would appear shadowy, erratic and jittery after we blink, a study has showed.
Blinking lubricates dry eyes and protects them from irritants. However, when we
blink, our eyeballs roll back in their sockets and do not always return to the
same spot when we reopen our eyes. This misalignment prompts the brain to
activate the eye muscles to realign our vision, the researchers said. The
finding showed that when we blink, our brain repositions our eyeballs so we can
stay focused on what we are viewing. ‘Our eye muscles are quite sluggish and
imprecise, so the brain needs to constantly adapt its motor signals to make
sure our eyes are pointing where they’re supposed to,’ said lead author Gerrit
Maus, Assistant Professor at Nanyang Technological University in Singapore.
‘Our findings suggest that the brain gauges the
difference in what we see before and after a blink and commands the eye muscles
to make the needed corrections,’ Maus added. For the study, healthy young
adults participated where they sat in a dark room for long periods staring at a
dot on a screen while infrared cameras tracked their eye movements and eye
blinks in real time. Every time they blinked, the dot was moved one centimetre
to the right. While participants failed to notice the subtle shift, the brain’s
oculomotor system registered the movement and learned to reposition the line of
vision squarely on the dot. After 30 or so blink-synchronised dot movements,
participants’ eyes adjusted during each blink and shifted automatically to the
spot where they predicted the dot to be. The study was published in the
journal Current Biology.
27.01.2017
We don’t grow when things are
easy; we grow when we face challenges
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