Watching the eclipse? Wear red and green to see optical illusion

The Purkinje effect may have the light playing tricks on you if you wear red and green during the total solar eclipse. (But don't forget your eclipse glasses!)

As space enthusiasts in some parts of Canada gear up to experience a once-in-a-lifetime total solar eclipse on Monday, they should know that red and green are optimal colours to wear during the event.

This is because of a phenomenon called the Purkinje effect, first described by Czech physiologist Johannes Purkinje in 1823.

Purkinje found that in bright environments, red colours appear more luminous than blue, but in low-light environments, those same blues appear much brighter than reds, according to a web book published by professor emeritus Peter Kaiser of York University.

Purkinje noticed this phenomenon while walking around in the early dawn. In the dim light, the red flowers around him appeared inky black, according to the Oxford Reference.

During the total solar eclipse, you should be able to see this phenomenon play out. Bright red clothing may appear darker and faded while blues and greens appear more vibrant.

This effect also occurs as day slowly shifts to night, especially in the twilight hours. But during the eclipse, the effect should appear even more pronounced as the shift from bright light to low light happens much more quickly, according to Jeff Horvis, an associate professor at the University of Waterloo’s School of Optometry and Vision Science.

“Things happen a little bit quicker. So you don’t really have time to adapt to all the changes in the light level,” Horvis told Global News.

Horvis recommends wearing red and green together, to see an even bigger contrast as the moon blocks out the sun during the total eclipse.