To view or not to view the solar eclipse
By Buffalo Medical Group | April 1 2024 | Uncategorized
To view or not to view the solar eclipse
David J. Rodman, M.D.
Ophthalmology
The eclipse is coming, and Buffalo is in a direct path for totality. Undoubtedly, there will be countless individuals who will be compelled to look at the sun that afternoon, hopefully with the recommended ISO 12312-2:2015 glasses.
In Buffalo, if we have a clear day with a dominant high-pressure system overhead, the moon will start blocking the sun at 2:04 PM and a four-minute totality will begin at approximately 3:18 PM with maximum blockage at 3:20 PM. Otherwise, we will find ourselves in an unusual cloudy but darkening mid-afternoon experience and the risk of ocular damage should be minimal.
Ocular disease and permanent retinal damage may occur by incorrectly viewing the eclipse. Our Ophthalmology practice has a significant number of patients with medical retinal problems including some with solar retinopathy damage to the retina.
Historically, solar retinopathy gained significant attention during the Vietnam War era, when prospective inductees for the armed services learned if they stared at the sun in the days prior to their physical exams, their vision was significantly decreased and uncorrectable with glasses. The examining doctors noted a yellow spot in the fovea of the retina. Suspicions were raised when an epidemic of these patients was noted at the induction centers.
Damage from sun gazing was known to the Greeks but similar effects with vision loss can also be caused by welding, laser pointers or even patient exposure to light during ophthalmic surgeries.
Generally, young patients without cataracts, or patients who do not require glasses for distance vision correction, are much more susceptible to solar retinopathy damage than any other group of individuals. Those who take photosensitivity increasing drugs, like tetracyclines, may also be at increased threat of retinal damage. Individuals may risk many months of decreased vision and possibly failure of the retina to completely heal or restore normal sight again.
We now know more about the pathology of solar radiation damage to the retina. Excessive solar radiation causes photochemical damage to several layers of the retina. Free radical formation likely plays a part and damage may be thermally enhanced by the infrared heating of tissues. Essentially, one may think of the solar eclipse exposure as similar to holding a magnifying glass in the sun to burn a leaf and start a fire.
Modern instrument testing allows a more detailed evaluation of the retina layers. Diagnosis of solar damage to the retina can be made by history of solar exposure and subsequent recovery followed with testing and monitoring of visual acuity. In addition, for patients that have other pathologies that need imaging, fluorescein angiography testing is available.
There are no therapeutic medications or treatments available for patients diagnosed with solar retinopathy. The final visual outcome is variable and unpredictable. Patients may always have decreased visual acuity if the retina is sufficiently damaged by the sun. The best way to view the eclipse will be via the media or with careful viewing using protective lenses. Avoid all but the briefest view of the sun prior to and after totality occurs. The more the sun is visible, the greater the chance that retinopathy will develop.