Blind Spot

A large blue and red cube frame that has purple and green information banners hanging between top and bottom bars of the cube. There are also square orange and white shapes hanging from the frame.

The human visual system compensates for a 'blind spot' on the retina.

How it works

Hold the panel about 30 cm (one ruler length) in front of your face. Stare at an icon on the panel and move markers into view to measure your blind spot.

Things to try or ask around the exhibit

Where is your blind spot?

Background

Your eyeballs have photoreceptors which receive light and create nerve signals for your brain. Small spots on each eyeball are missing photoreceptors, because they are attached to a tiny bundle of arteries, veins and optic nerve. This is called the blind spot.

Any light that hits the blind spot cannot be detected by the brain. Usually, your brain ‘fills in’ the gaps, so you don’t notice your blind spot at all. This is why the two bars seem to merge into one bar.

Finding the science in your world

Occasionally, the blind spot causes people to not notice something flying towards their head, such as a ball in a sporting match, but this is also partly caused by attention being focused on other events as well as the blind spot not detecting and sending signals.