Monday’s partial eclipse of the sun is sure to be a tempting sight.
The danger is real enough that Albuquerque Public Schools sent out three notices to every school this week – and posted them on its website – that “teachers need to be aware of the safety issues that surround viewing an eclipse and carefully plan and follow the instructions and safety guidelines provided by the sources suggested to prevent any accidents.”
Several thousand students will be at recess or on lunch break during the partial eclipse times on Monday from 10:21 a.m. beginning to 1:13 p.m. finish.
“Please note that the only acceptable eye protection are Eclipse Viewing Glasses, or a pinhole camera (links to making a simple camera were provided in the notice). No other form of eyewear is acceptable, no exceptions!” one notice said.
It said students without acceptable protection “will NOT be allowed outside to view the eclipse,” and principals were told to make sure parents were notified of each school’s safety and viewing plan, including a choice to opt out of activities.
But finding eclipse viewing glasses will be a challenge – calls to several local businesses turned up just one that may have a shipment in Friday.
About 75 percent of the sun will be covered by the moon at the peak of the eclipse, at 11:45 a.m. in Albuquerque.
During this time, the sun will appear less bright, but its light will be just as damaging to the eyes.
“If somebody is watching the solar eclipse without protection, it can cause severe damage,” warned Dr. Arup Das, chief of ophthalmology at the University of New Mexico Health Sciences Center.
Das’ specialty is the retina, the part of the eye that senses light and is damaged by the sun’s direct rays.
When light enters the eye, it is concentrated in a 1.5-millimeter-wide area at the back of the eyeball called the fovea, Das said. When direct sunlight reaches the fovea, a chemical reaction known as phototoxicity occurs that damages the cells of the fovea.
The damage done depends on how long the exposure is.
Keep in mind, “long” exposure to the sun’s direct rays is just a few seconds, Das said.
Normally, the body has a variety of automatic responses to gazing at sunlight: The pupil – the hole in the center of the eye that allows light in – shrinks, and the urge to blink and look away sets in.
“In a partial eclipse, people can look at the sun with more ease and comfort,” said Das.
The sun won’t appear as bright, essentially tricking your eyes into thinking it’s safe to look.
It’s not, though; the same damaging, ultraviolet rays from the sun are being emitted.
The pupils won’t shrink, allowing even more of the dangerous rays to contact the fovea.
Das said that generally, the fovea can repair itself after short exposure to the sun over the course of weeks or months.
Symptoms include visual distortion or a central scotoma, a black spot visible in the center of vision.
But in the majority of cases, these cannot be cured.
In some circumstances, what’s called a macular hole can develop where a perforation of the retina occurs, which requires surgery to fix.
To protect your eyes while watching the eclipse, special filters are necessary.
The American Society of Retina Specialists recommends that filters used to watch the eclipse transmit just 0.003 percent of visible light; that’s why those special solar viewing glasses don’t let you see much else.
To ensure the glasses you’ve chosen are effective, they should be 12312-2 certified by the International Organization for Standardization, or ISO. This should be marked somewhere on the glasses.
Das warned that sunglasses, although they offer some ultraviolet protection, are not sufficient.
Anything used to photograph or observe the eclipse, like a cellphone camera or telescope, must also have a filter placed over it, Das said.