Eye Safety During a Total Solar Eclipse

Except during the brief total phase of a total solar eclipse, when the Moon completely blocks the Sun’s bright face, it is not safe to look directly at the Sun without specialized eye protection for solar viewing.

The total eclipse will last for three minutes and 14 seconds in the North Country, but the partial eclipse – when the moon begins to move in front of the sun – will last about 45 minutes before and after that time.

Viewing any part of the bright Sun through a camera lens, binoculars, or a telescope without a special-purpose solar filter secured over the front of the optics will instantly cause severe eye injury.

When watching the partial phases of the solar eclipse directly with your eyes, which happens before and after totality, you must look through safe solar viewing glasses (“eclipse glasses”) or a safe handheld solar viewer at all times.

Eclipse glasses are NOT regular sunglasses; regular sunglasses, no matter how dark, are not safe for viewing the Sun. Safe solar viewers are thousands of times darker and ought to comply with the ISO 12312-2 international standard. NASA does not approve any particular brand of solar viewers. When choosing a set of solar glasses or filters, look closely at the manufacturing information and search for three markings: the ISO logo, ISO-12312-2:2015 safety standard, and approval from the American Astronomical Society. Solar eclipse glasses providing proper protection should be approved by the American Astronomical Society (AAS).

Always inspect your eclipse glasses or handheld viewer before use; if torn, scratched, or otherwise damaged, discard the device. Always supervise children using solar viewers.

Do NOT look at the Sun through a camera lens, telescope, binoculars, or any other optical device while wearing eclipse glasses or using a handheld solar viewer — the concentrated solar rays will burn through the filter and cause serious eye injury.

Do NOT use eclipse glasses or handheld viewers with cameras, binoculars, or telescopes. Those require different types of solar filters. When viewing the partial phases of the eclipse through cameras, binoculars, or telescopes equipped with proper solar filters, you do not need to wear eclipse glasses. (The solar filters do the same job as the eclipse glasses to protect your eyes.)

You can view the eclipse directly without proper eye protection only when the Moon completely obscures the Sun’s bright face – during the brief and spectacular period known as totality. (You’ll know it’s safe when you can no longer see any part of the Sun through eclipse glasses or a solar viewer.)

As soon as you see even a little bit of the bright Sun reappear after totality, immediately put your eclipse glasses back on or use a handheld solar viewer to look at the Sun.

Chair of Rochester Regional Health’s Department of Ophthalmology, and ophthalmologist https://www.rochesterregional.org/physician-directory/z/zatreanu-luca, explains how to recognize the signs of eye damage from the sun and safe ways to watch the eclipse.

Recognizing Signs of Eye Damage

Eye damage from the sun is called solar retinopathy; damage to the retina resulting from sunlight.

Sunlight contains ultraviolet (UV) light rays that can cause specific damage to retinal tissue. This happens through a photochemical reaction that produces compounds that are toxic to retinal tissue in high concentrations. The cells inside the retina that capture light become damaged by these toxic compounds.

Immediate signs of solar retinopathy might include blurry vision, blind spots, or vision distortion (seeing straight lines as wavy.)

If you start to experience any of these symptoms for more than 30 minutes, it may likely be a sign of solar retinopathy. This is not considered an emergency situation that requires same-day treatment.

“There is no treatment that is known to be effective at treating solar retinopathy,” Dr. Zatreanu said. “The good news is that many of the mild or moderate cases do resolve on their own. It just takes time. However, some cases lead to permanent blind spots or vision loss.”

Eye damage from the sun, specifically solar retinopathy, can take two to six months to heal or, in some cases, resolve.

Risk Factors for Eye Damage

Oddly, people who have naturally good vision face the most risk for sustaining eye damage from the sun.

People with uncorrected 20/20 vision have a higher risk because light rays naturally focus directly onto their retinas. People who are nearsighted or farsighted have light rays focus in front of or behind their retinas, respectively, which provides a small amount of protection.

Other risk factors include eye pigmentation and certain types of medication. The darker the pigmentation of the retina, the more protection a person’s eyesight has against damage from light rays. Medications like doxycycline can make a person’s eyes more sensitive to light damage.

“If you are unsure about your eye health, now is a good time to get your eyes checked and establish a baseline for your regular vision,” https://www.linkedin.com/in/lucazatreanu/ said. “If you have any concerns or health issues that arise, you know where you started from.”

Safety Tips for Children

If they choose to witness the solar eclipse on April 8: wear approved protective eyewear that fully cover your field of vision.

To protect children in your care, keep children indoors during the eclipse event from 2 - 4 p.m. with curtains and blinds closed.

Avoid picking up children from childcare/school during eclipse hours; if not possible, take precautions to protect child’s eyes.

If you don’t want to miss out, please consider viewing the eclipse virtually through nasa’s live stream event at https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/safety

Sources: NASA and St. Lawrence Health (SLH), an affiliate of Rochester Regional Health. For information about SLH’s eye care specialist, visit https://www.stlawrencehealthsystem.org/provider-directory and search the specialty field for Ophthalmology or Optometry.