Eclipse experiments: Wear red or green during the April 2024 eclipse for a fun science lesson

The first total solar eclipse of 2024 is in April and it will be the only solar eclipse this year that will have a path of totality stretching across the U.S. It’s been nicknamed “The Great North American Eclipse.”

Florida isn’t in the path of totality, but depending on where you are in the state, you might be able to see a little over half of the sun being covered by the moon.

Although your location has everything to do with how well you’ll be able to see the eclipse, it isn’t the only thing that determines what you see on eclipse day. And eclipse glasses aren't the only accessory that you'll need to experience this natural phenomenon to the fullest.

Did you know that what color you choose to wear can enhance your eclipse viewing experience?

If you’re planning on watching the eclipse with friends and family, tell them to wear red or green and see what happens.

Here’s the science behind why and how our eyes see colors differently in low light.

What are the differences between rod and cone cells?

You might remember from a high school anatomy class that there are two kinds of photoreceptors in your eyes: rods and cones. 

More simply put, photoreceptors are nerves that take in light and tell your brain what you’re seeing.

There are 6 million to 7 million cones, or cone cells, in your eyes that help you see colors clearly in well-lit scenarios, like in regular daylight. Cones are mostly concentrated in one place in the back of your eye (the retina). When your cones are in charge, it’s called photopic vision.

Psychology and vision studies of how human eyes perceive color have found that cone cells don’t function properly in low lighting, so that’s when the other photoreceptors in your eyes (the rods, or rod cells) take over. There are around 120 million rods in your eyes that are in a different place within your eye, in the periphery. And their location makes them better for seeing in dim light.

Although rod cells allow you to see in low light, they aren’t very sharp when it comes to helping your brain process colors. When your rods are in charge, it’s called scotopic vision.

Rods are one thousand times more sensitive to light than cones. Since rods don’t process color the way cones do, they are responsible for a different job: telling your brain how bright it is and adjusting your vision accordingly. 

Mesopic vision is what happens in the in-between. This is when your rods and cones work together since it’s the transitional stage between photopic and scotopic vision.

What do you see during a solar eclipse?

Here’s what all this eyeball science has to do with a solar eclipse.

There’s a four-to-five-minute window of time before an eclipse reaches totality, when your eyes are functioning in the in-between zone (the mesopic vision zone).

During the mesopic vision zone of an eclipse, your surroundings may look grayish and lack color. It's most noticeable with warm colors, like red or orange.

But remember, when your rods take over in dim lighting, your eyes still pick up green and blue hues. 

This natural phenomenon of how our eyes respond to specific colors with a change in lighting even has a cool name. It’s called the Purkinje effect, named for 18th century Czech experimental physiologist Jan Evangelista Purkinje who found that the perceived vibrancy of red objects fade faster than blue objects of the same brightness.

Green, specifically, will look very bright against the dim surroundings as the moon covers the sun. 

If you want to experiment with color and optical science this eclipse, have one of your friends or family wear green and dress yourself in something red (or vice versa). You can compare how the red clothing seems to fade to a shade of gray as the green clothing seems to get brighter.

But remember, do not look directly at the sun without protective glasses or special lenses on your camera, phone camera, binoculars or telescope. We won't see full totality anywhere in Florida so there will be no point when it will be safe to look at the solar eclipse with the naked eye.

Protect your eyes:Warby Parker offering free eclipse glasses. Here's when and where to get them in Florida

Will the 2024 eclipse be visible in Florida?

Florida isn’t in the direct path of the total eclipse.

The path of totality of the Great North American Eclipse will start between New Zealand and Mexico in the South Pacific Ocean, pass from Mexico into Oklahoma, and travel northeast (diagonally) across the country. The path of totality will cross the New England region of the U.S. and then a portion of Canada, before ending in the Atlantic Ocean near the French and Spanish coasts.

While we're not in the path of totality, we'll still be able to see some of it from Florida. From just over half of the sun to over 3/4 of it will be obscured by the moon from our angle, depending on where you are in the state.