As the 2024 total solar eclipse passes over Kent, Ohio, on Monday, April 8, Kent State University students, faculty and staff have the unique opportunity to witness an optical illusion known as the Purkinje effect.
First discovered by physiologist Jan Evangelista Purkyně, the Purkinje effect alters our perception of colors, especially red and green tones. Physics graduate research assistant Alex Clevinger explains how this process takes place.
“Our eyes perceive light with cones and rods in our eyes. Our eyes use the cones during the day and the rods at night. During times when the sun goes down, our eyes transition from using rods to cones,” Clevinger said.
In the moments leading to totality, the surroundings may take on a darker, grayish tone, providing the opportunity to observe the Purkinje effect. As the moon slowly blocks the sun, it diminishes light and our eyes adapt and trigger shift in color perception like dusk time.
“This shift causes our eyes to be more sensitive to blue colors. Red colors appear darker relative to other colors,” Clevinger said. “This effect will be more pronounced during totality because our eyes will have to adjust quickly, and they aren’t used to doing that in the middle of the day.”
Kathryn Novak, assistant professor in the School of Fashion, is excited to experience the color theory that happens with the Purkinje effect.
“I plan on wearing red and green and carefully taking off my glasses to enjoy the full effect of the Purkinje effect,” Novak said. “I am consistently encumbered by metamerism, where colors look different in various light sources since the room I get ready in has a golden hue. Then in natural light, I find the colors do not match. It will be refreshing to see the colors change intentionally for once.”
The Purkinje effect isn’t the only thing to look out for during this historic event. Clevinger has several recommendations to watch out for.
“The brightest object in the sky will be Venus. Several other planets will be visible such as Jupiter, Mars and Saturn,” Clevinger said. “We should also look at the ground because we may see ‘snake-bands’ of light. These shimmers are caused by turbulence in the atmosphere.”
Don’t forget it's essential to prioritize eye safety during the eclipse. Once you’ve viewed the Purkinje effect, remember to replace your glasses before looking at the sun again. Always wear proper eclipse glasses when looking directly at the sun to avoid permanent eye damage.
Even with these optical illusions and stargazing opportunities aside, Clevinger stresses that this will be a life-changing memory for many.
“I think the most special part of the event will be the few minutes that the world will stand still. Everyone will stop what they are doing and look up in the sky in awe at the beauty of it all,” Clevinger said. “It truly will be a once-in-a-lifetime event.”
To verify if your glasses are safe to use, look for an approved manufacturer and an ISO 12312-2 certification listed on the inside of the glasses. Eclipse glasses are NOT regular sunglasses. Regular sunglasses, no matter how dark, are not safe for viewing the sun.
Glasses are being distributed on Kent Campus starting Friday, April 5 for students. The bookstore will distribute to students with their FLASHcard present. Glasses also will be distributed at Risman Plaza starting at 1 p.m.; first come, first served.