Dr. Mike E. Harris
Dr. Nathan D. Edwards
visionsource-casper.com
HOW TO VIEW
the 2017 Solar Eclipse Safely
A SOLAR ECLIPSE occurs when the Moon blocks any part of the Sun. On Monday, August 21, 2017,
a solar eclipse will be visible (weather permitting) across all of North America. The whole continent
will experience a partial eclipse lasting 2 to 3 hours. Halfway through the event, Casper—and those
on the narrow path from Oregon to South Carolina—will experience a brief total eclipse. The Moon
HowtoViewthe2017SolarEclipseSafely
will
completely block the Sun for up to 2 minutes and 40 seconds, turning day into night and making
AsolareclipseoccurswhentheMoonblocksanypartoftheSun.OnMonday,August21,2017,asolareclipsewillbe
visible
the otherwise hidden solar corona (the Sun’s outer atmosphere), one of nature’s most
visible(weatherpermitting)acrossallofNorthAmerica.Thewholecontinentwillexperienceapartialeclipselasting2to
3hours.Halfwaythroughtheevent,anyonewithinaroughly70-mile-widepathfromOregontoSouthCarolina
awesome
sights. Bright stars and planets will become visible as well.
(http://bit.ly/1xuYxSu)willexperienceabrieftotaleclipse,whentheMooncompletelyblockstheSun’sbrightfaceforup
to2minutes40seconds,turningdayintonightandmakingvisibletheotherwisehiddensolarcorona—theSun’souter
atmosphere—oneofnature’smostawesomesights.Brightstarsandplanetswillbecomevisibleaswell.
LOOKING DIRECTLY AT THE SUN IS UNSAFE except during the brief total
phase of a solar eclipse (totality), when the Moon entirely blocks the Sun’s
bright face, which will happen only within the narrow path of totality.
The only safe way to look directly at the uneclipsed or partially eclipsed Sun is through specialpurpose solar filters, such as “eclipse glasses” (example shown at left) or hand-held solar viewers.
LookingdirectlyattheSunisunsafeexceptduringthebrieftotalphaseofasolareclipse(“totality”),whentheMoon
Homemade
filters or ordinary sunglasses, even very dark ones, are not safe for looking at the Sun.
entirelyblockstheSun’sbrightface,whichwillhappenonlywithinthenarrowpathoftotality(http://bit.ly/1xuYxSu).
To date, four manufacturers have certified that their eclipse glasses and
TheonlysafewaytolookdirectlyattheuneclipsedorpartiallyeclipsedSunisthrough
hand-held solar viewers meet the ISO 12312-2 international standards for
special-purposesolarfilters,suchas“eclipseglasses”(exampleshownatleft)orhand-held
HowtoViewthe2017SolarEclipseSafely
solarviewers.Homemadefiltersorordinarysunglasses,evenverydarkones,arenotsafe
such products: Rainbow Symphony, American Paper Optics, Thousand Oaks
forlookingattheSun.Todatefourmanufacturershavecertifiedthattheireclipseglasses
AsolareclipseoccurswhentheMoonblocksanypartoftheSun.OnMonday,August21,2017,asolareclipsewillbe
Optical, and TSE 17. Family Vision Clinic will be providing eclipse glasses
andhand-heldsolarviewersmeettheISO12312-2internationalstandardforsuch
visible(weatherpermitting)acrossallofNorthAmerica.Thewholecontinentwillexperienceapartialeclipselasting2to
products:RainbowSymphony,AmericanPaperOptics,ThousandOaksOptical,andTSE17.
at our office for patients.
3hours.Halfwaythroughtheevent,anyonewithinaroughly70-mile-widepathfromOregontoSouthCarolina
(http://bit.ly/1xuYxSu)willexperienceabrieftotaleclipse,whentheMooncompletelyblockstheSun’sbrightfaceforup
• Alwaysinspectyoursolarfilterbeforeuse;ifscratchedordamaged,discardit.Readandfollowanyinstructions
to2minutes40seconds,turningdayintonightandmakingvisibletheotherwisehiddensolarcorona—theSun’souter
printedonorpackagedwiththefilter.Alwayssupervisechildrenusingsolarfilters.
atmosphere—oneofnature’smostawesomesights.Brightstarsandplanetswillbecomevisibleaswell.
•
StandstillandcoveryoureyeswithyoureclipseglassesorsolarviewerbeforelookingupatthebrightSun.After
glancingattheSun,turnawayandremoveyourfilter—donotremoveitwhilelookingattheSun.
DonotlookattheuneclipsedorpartiallyeclipsedSunthroughanunfilteredcamera,telescope,binoculars,orother
opticaldevice.Similarly,donotlookattheSunthroughacamera,atelescope,binoculars,oranyotheroptical
Total Eclipse (no filter)
Partial Eclipse (USE FILTER)
Partial Eclipse (USE FILTER)
devicewhileusingyoureclipseglassesorhand-heldsolarviewer—theconcentratedsolarrayswilldamagethe
filterandenteryoureye(s),causingseriousinjury.Seekexpertadvice
fromanastronomerbeforeusingasolarfilterwithacamera,atelescope,
A total solar eclipse is about as bright as the full Moon—and just as safe to look at.
binoculars,oranyotheropticaldevice.
LookingdirectlyattheSunisunsafeexceptduringthebrieftotalphaseofasolareclipse(“totality”),whentheMoon
But the Sun at any other time is dangerously bright; view it only through special-purpose safe solar filters.
•entirelyblockstheSun’sbrightface,whichwillhappenonlywithinthenarrowpathoftotality(http://bit.ly/1xuYxSu).
Ifyouarewithinthepathoftotality(http://bit.ly/1xuYxSu),removeyour
solarfilteronlywhentheMooncompletelycoverstheSun’sbrightface
TheonlysafewaytolookdirectlyattheuneclipsedorpartiallyeclipsedSunisthrough
anditsuddenlygetsquitedark.Experiencetotality,then,assoonasthe
special-purposesolarfilters,suchas“eclipseglasses”(exampleshownatleft)orhand-held
brightSunbeginstoreappear,replaceyoursolarviewertoglanceatthe
remainingpartialphases.solarviewers.Homemadefiltersorordinarysunglasses,evenverydarkones,arenotsafe
forlookingattheSun.Todatefourmanufacturershavecertifiedthattheireclipseglasses
AnalternativemethodforsafeviewingofthepartiallyeclipsedSunispinholeprojection.Forexample,crossthe
andhand-heldsolarviewersmeettheISO12312-2internationalstandardforsuch
•
TIPS FOR VIEWING THE ECLIPSE SAFELY
LookingdirectlyattheSunisunsafeexceptduringthebrieftotalphaseofasolareclipse(“totality”),whentheMoon
• Always
inspect your solar filter before use. If scratched or damaged, discard it. Read and
entirelyblockstheSun’sbrightface,whichwillhappenonlywithinthenarrowpathoftotality(http://bit.ly/1xuYxSu).
follow any instructions printed on or packaged with the filter. Always supervise children
TheonlysafewaytolookdirectlyattheuneclipsedorpartiallyeclipsedSunisthrough
special-purposesolarfilters,suchas“eclipseglasses”(exampleshownatleft)orhand-held
• Stand still and cover your eyessolarviewers.Homemadefiltersorordinarysunglasses,evenverydarkones,arenotsafe
with your eclipse glasses or solar viewer before looking up at
forlookingattheSun.Todatefourmanufacturershavecertifiedthattheireclipseglasses
the bright Sun. After glancing at
the Sun, turn away and remove your filter—do not remove it
andhand-heldsolarviewersmeettheISO12312-2internationalstandardforsuch
products:RainbowSymphony,AmericanPaperOptics,ThousandOaksOptical,andTSE17.
while looking at the Sun.
using solar filters.
• look
Alwaysinspectyoursolarfilterbeforeuse;ifscratchedordamaged,discardit.Readandfollowanyinstructions
• Do not
at the uneclipsed or partially eclipsed Sun through an unfiltered camera,
printedonorpackagedwiththefilter.Alwayssupervisechildrenusingsolarfilters.
telescope,
binoculars, or other optical device. Similarly, do not look at the Sun through a
•
StandstillandcoveryoureyeswithyoureclipseglassesorsolarviewerbeforelookingupatthebrightSun.After
glancingattheSun,turnawayandremoveyourfilter—donotremoveitwhilelookingattheSun.
camera, a telescope, binoculars, or any other optical device while using your eclipse glasses
or hand-held
solar viewer—the concentrated solar rays will damage the filter and enter your
•
DonotlookattheuneclipsedorpartiallyeclipsedSunthroughanunfilteredcamera,telescope,binoculars,orother
eye(s), causing
serious injury. Seek expert advice from an astronomer before using a solar
opticaldevice.Similarly,donotlookattheSunthroughacamera,atelescope,binoculars,oranyotheroptical
filter withdevicewhileusingyoureclipseglassesorhand-heldsolarviewer—theconcentratedsolarrayswilldamagethe
a camera, a telescope, binoculars, or any other optical device.
filterandenteryoureye(s),causingseriousinjury.Seekexpertadvice
• If you arefromanastronomerbeforeusingasolarfilterwithacamera,atelescope,
within the path of totality (like Casper), remove your solar
binoculars,oranyotheropticaldevice.
filter only
when the Moon completely covers the Sun’s bright face and
• Ifyouarewithinthepathoftotality(http://bit.ly/1xuYxSu),removeyour
it suddenly
gets quite dark. Experience totality, then, as soon as the
solarfilteronlywhentheMooncompletelycoverstheSun’sbrightface
bright Sun
begins to reappear, replace your solar viewer to glance at
anditsuddenlygetsquitedark.Experiencetotality,then,assoonasthe
brightSunbeginstoreappear,replaceyoursolarviewertoglanceatthe
the remaining
partial phases.
remainingpartialphases.
AnalternativemethodforsafeviewingofthepartiallyeclipsedSunispinholeprojection.Forexample,crossthe
An alternative
method for safe viewing of the partially eclipsed Sun is pinhole projection. For
outstretched,slightlyopenfingersofonehandovertheoutstretched,slightlyopenfingersoftheother.Withyourback
example,
cross the outstretched, slightly open fingers of one hand over the outstretched, slightly
totheSun,lookatyourhands’shadowontheground.Thelittlespacesbetweenyourfingerswillprojectagridofsmall
imagesontheground,showingtheSunasacrescentduringthepartialphasesoftheeclipse.
open fingers
of the other. With your back to the Sun, look at your hands’ shadow on the ground.
The littleAsolareclipseisoneofnature’sgrandestspectacles.Byfollowingthesesimplerules,youcansafelyenjoytheviewand
spaces between your fingers will project a grid of small images on the ground, showing
the Sunberewardedwithmemoriestolastalifetime.Moreinformation:
as a crescent during the partial phases of the eclipse.
eclipse.aas.orgeclipse2017.nasa.gov
A solar eclipse is one of nature’s grandest spectacles. By following these simple rules, you can
Thisdocumentdoesnotconstitutemedicaladvice.Readerswithquestionsshouldcontactaqualifiedeye-careprofessional.
safely enjoy the view and be rewarded with memories to last a lifetime.
For more information, visit eclipse.aas.org and eclipse2017.nasa.gov
HowtoViewthe2017SolarEclipseSafely
This document does not constitute medical advice. Readers with questions should contact a qualified eye-care professional.
AsolareclipseoccurswhentheMoonblocksanypartoftheSun.OnMonday,August21,2017,asolareclipsewillbe
visible(weatherpermitting)acrossallofNorthAmerica.Thewholecontinentwillexperienceapartialeclipselasting2to
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