An optics professor explains how eclipse glasses protect your eyes from the sun’s light during an eclipse. Properly protecting your eyes during a solar eclipse is crucial for avoiding long-term damage to your vision. In anticipation of the total solar eclipse happening in Rochester, New York, on April 8, 2024, James Zavislan, a professor of optics and of biomedical engineering and an associate professor of ophthalmology at the University of Rochester, wants everyone to understand the risks involved and how to have a safe, enjoyable eclipse experience.
Zavislan, an expert in optical system analysis and optical engineering, sheds light on the science behind solar eclipse glasses. He emphasizes the importance of eclipse glasses in blocking harmful portions of the solar spectrum, stating, "Eclipse glasses attenuate, or filter out, the portions of the solar spectrum that could injure the eye."
Regarding the behavior of our eyes during a solar eclipse, Zavislan explains, "In general, when we look up at the sun, it’s uncomfortably bright, so our pupils constrict, and at some point, we just look away." He advises that during the eclipse, glasses should only be removed during totality when no white portion of the sun is visible.
To ensure the safety of viewers, Zavislan highlights the significance of using certified eclipse glasses, stating, "You want to make sure it meets the standards set by the International Organization for Standardization, or ISO. If you look on the inside of the glasses, you should see an ISO number 12312-2 stamped there."
When it comes to using regular sunglasses for viewing an eclipse, Zavislan warns against it, noting that sunglasses are not designed to protect the eyes from direct viewing of the sun during an eclipse.
In terms of capturing the eclipse through a cellphone camera, Zavislan advises against pointing the camera directly at the sun, as it can be harmful to the device. He suggests taking a quick picture during totality if necessary, but emphasizes the importance of prioritizing the viewing experience over photography.
Zavislan also discusses the testing process conducted at the Institute of Optics to ensure the safety of eclipse glasses, stating, "We performed additional testing at the Institute of Optics." Additionally, he shares insights into the unique features of the upcoming April 8 eclipse, mentioning the potential visibility of the sun’s corona streamers when the sun’s main disk is blocked.
As the solar eclipse approaches, Zavislan's expertise serves as a guide for safely experiencing this celestial event while highlighting the essential role of eclipse glasses in protecting one's vision.
