Fake eclipse glasses are back.  People selling them online was also a problem before the last U.S. eclipse in 2017.  If they’re not legit, you could BURN YOUR EYEBALLS OUT.  It can cause permanent damage to your retinas.

If you’re not fully confident in the glasses you bought, here’s what to do.  “Scientific America” says there’s a three-step test you can do to make sure your eclipse glasses are legit.

1.  Put them on indoors and look around.  You should only be able to see very bright lights.  Like a halogen bulb, or an iPhone flashlight shined directly at you.

2.  Take them outside, but don’t look at the sun yet.  It should be too dark to see distant hills, trees, or even the ground.

3.  Take a quick glance at the sun.  It shouldn’t hurt at all.  You should be able to comfortably look at the sun and see a bright, sharp-edged disk.  If it feels hard at all, stop immediately.  And only do it if your glasses pass the other two tests first.

If they pass all three of those tests, you’re probably good to go.  But be careful, because it’s not foolproof.  You might still want to be cautious, and only look at the eclipse for a few seconds every minute or so.

(Scientific American)