By Mark Nakano, OD
On August 21, 2017, a solar eclipse will be visible (weather permitting) across all of North America. The entire continent will experience a partial eclipse lasting 2 to 3 hours. Anyone within a 70 mile wide path stretching from Oregon to South Carolina will experience a total solar eclipse; the moon completely blocks the sun’s bright face for approximately 3 minutes. The total phase of the eclipse will not be visible in Orange County, but can be observed here as a partial solar eclipse. The approximate time that this event will occur is 10:21 a.m.
Looking directly into the sun is unsafe, except during the brief total eclipse phase. Some of the damage that can occur from viewing this event without proper protection is solar retinopathy, distorted vision or altered color vision. All of the retinal damage is the direct result from prolonged staring at the sun and its harmful ultraviolet rays. Unfortunately, there is currently no single treatment for solar retinopathy.
For safe viewing of the solar eclipse, the American Optometric Association recommends special-purpose filters, such as eclipse glasses that meet the ISO 12312-2 international standard. Solar eclipse glasses are made with a special filter that has a thin layer of chromium alloy or aluminum deposited on the surface that reduces both visible and near-infrared radiation. Safe solar filters transmit less than 0.003% of visible light and no more than 0.5% of the near-infrared radiation.
Eclipse viewing glasses and handheld solar viewers should meet all of the following criteria:
- Have Certified information with ISO 12312-2 International Standard
- Have Manufacturer’s name and address printed somewhere on the product
- NOT to be used if they are older than 3 years, or have scratches or wrinkled lenses
- NOT to use homemade filters
- Ordinary sunglasses – even very dark ones – should NOT be used
The University Eye Center at Ketchum Health is located at 5460 E. La Palma Ave. in Anaheim Hills, at the Imperial Hwy exit off the 91 freeway.