There is an old saying among ER docs to beware of a full moon because of the crazy things that happen in the ER.
But Monday's spectacular eclipse of the sun may provide a different kind of show--one that ER doctors could potentially face Tuesday, due to people looking directly at the eclipse or from wearing improper eye protection.
A number of emergency physicians believe that this rare natural wonder could lead to an uptick in emergency visits in certain locales across the country where people may be lured by false sense of security that they can safely watch the eclipse without proper eye protection, defined as when the moon completely covers the sun. Any eye damage would likely manifest 12 hours later, not at the time of viewAccording to officials at NASA, for persons who are situated in what is known as the path of “totality,” --when the moon completely blocks the sun’s face and reveals its corona, --it will be safe to directly view the eclipse without eye protection. But the majority of people in the U.S. are not in that path, and those who choose to peer at the eclipse for even a few seconds without certified protective eyewear, face the potential for potentially permanent blindness.
A recent JAMA Opthalmology editorial reinforces the cautions that people should take who reside in the path of totality and elsewhere, and discredits the misconception "that an eclipse allows safe viewing of the sun", without the use of proper eye protection.
Sun rays escaping when the moon completely covers the sun can result in two distinct types of injury: direct thermal injury via near infrared rays that are not visible to the naked eye, and photochemical toxicity from visible rays that result in reactive oxygen species and free radicals that can destroy retinal tissue vital for central vision.
The risk for developing retinal injury and subsequent blindness ultimately depends upon the duration and angle of exposure to the sun’s rays. Since there are no pain receptors in the retina as there are on the skin, there is no way to known initially if you may have injured retinal tissue. While there may be some initial flashes of light, it’s generally about 12 hours later when visual complaints develop, according to most eye experts.
It’s the central part of the retina, an area known as the fovea within the macula, that is most at risk in the setting of directly viewing the eclipse without proper protection. Densely packed with specialized visual cells known as cones, the fovea is responsible for sharp central vision, important for detail when reading and driving.ing.
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