On August 21, 2017, the United States witnessed an event that happens only once in a lifetime – a total solar eclipse. Millions of people across the country watched in awe as the moon fully blocked the sun, creating an unforgettable moment of darkness in the middle of the day. However, the dazzling spectacle of the eclipse can be dangerous for your eyesight if you don’t take the necessary precautions. In this article, we’ll explore how to observe the eclipse safely and how to protect your vision from the sun’s harmful rays. So, turn around, bright eyes, and let’s get started.
On Thursday morning, a solar eclipse will occur throughout Australia. The Ningaloo region of Western Australia will have the best view of the phenomenon, with thousands of people expected to visit the small coastal town of Exmouth. It is important to take steps to protect your eyes from solar retinopathy, permanent eye damage caused by looking directly at the sun. Experts advise people to never look at the sun or an eclipse with the naked eye, but to instead use approved solar eclipse glasses that meet an international safety standard known as ISO 12312-2. This type of eye damage, also known as sun blindness, has been recognised since Ancient Greece, affecting many astronomers including Sir Isaac Newton.
Solar retinopathy is damage to the back of the eye caused by exposure to intense light. It can be caused by sungazing or eclipse viewing, but can also result from welding without a shield, looking at laser pointers, and from some surgical and photographic lighting. A process called “phototoxicity” happens when the energy in the light forms damaging free radicals and reacts with oxygen within the retina. This disrupts the retina’s supportive cells as well as blood vessels beneath, leading to permanent loss of central vision. Although some wavelengths of light that cause solar retinopathy are not visible to humans, they can cause damage in as little as a few seconds.
There is no proven treatment for solar retinopathy. Steroid medications have been tried without evidence of success, and may make things worse in some patients. Antioxidant medications may be used in some eye diseases, but there are no studies showing a benefit in solar retinopathy. Vision may improve over time without treatment, but many patients are left with residual deficits. Therefore, the mainstay of management is prevention.
It is advised to only purchase and use approved eclipse viewing glasses that will absorb the appropriate wavelengths of visible, ultraviolet and infrared light, and to never use sunglasses, polaroid filters, welding shields, X-ray film, neutral density filters, red glass filters, mobile phones, or homemade sun filters. Eclipse glasses must fit your face properly without any gaps that let light in. If any symptoms, such as blurred vision or altered colour vision in one or both eyes within one to two days of exposure, occur, people must stop eclipse viewing and use dark sunglasses and painkillers for light sensitivity and headaches. They must also arrange an urgent appointment with an ophthalmologist or a medical professional.
A total solar eclipse may potentially be viewed without eye protection for a brief period while the moon completely covers the sun (the period of totality). However, it is advised to remove eclipse glasses only after totality has commenced and to keep observing the remaining partial eclipse with the glasses on while being mindful that totality will only occur over the Ningaloo region.
While a solar eclipse is a rare occurrence and people may want to observe it, following the right advice will ensure their safety. It is important to purchase and use only approved viewing glasses, as eye damage from solar retinopathy is permanent and lifelong, and there is no effective treatment.
