Does mylar deteriorate over time?

[RobN]

I'm asking this because I have found some old mylar eclipse glasses from 1999, which I may use for tomorrow's partial eclipse, and I don't want to fry my eyes.

 

[Dantassii]

I'm asking this because I have found some old mylar eclipse glasses from 1999, which I may use for tomorrow's partial eclipse, and I don't want to fry my eyes.

You should NEVER look directly at the sun, no matter what.

Dantassii
HUMONGOUS IMS shipbuilder

 

[francisdrake]

Check if there are tiny white spots in the mylar when holding it up against a lamp.
Maybe use a magnifying glass to examine. Such defects would allow unfiltered sun rays to enter your eye, not a good thing.

I have to check myself, but will probably also use the mylar shades from 1999

 

[Kyle]

You should NEVER look directly at the sun, no matter what.

Dantassii
HUMONGOUS IMS shipbuilder

If you have a mylar filter you can look at the Sun. I have a mylar filter for my 8" Dobsonian and I use it to look at the Sun all the time.

 

[TachyonDriver]

A pair of decent welding goggles. They block the harmful UV from electric arc welding.

 

[C3PO]

A pair of decent welding goggles. They block the harmful UV from electric arc welding.

Not recommended. Welding goggles come in a wide variety from oxyacetylene to TIG welding, and if you don't know the difference you can do a lot of harm. I have a set of the darkest guards I could lay my hands on, and I found it very uncomfortable to look at the Sun on a clear day, even for less than a second.

There are plenty of safe ways to view the Sun. Being creative is not a good idea in this area.

From the link posted by Ripley in the eclipse thread:

As a kid, did you ever take a magnifying glass out into the sun and burn leaves? If so, you probably remember that when the focused sunlight coming through the lens was refracted and concentrated to a small spot, the energy available there was truly remarkable. Guess what? You have a lens just like that in your eye. If you look at the sun, your eye-lens will concentrate the sun's light and focus it to a very small spot on the back of your retina. This can cause permanent eye damage or blindness. Additionally, there are no pain sensors back there so you won't even know it's happening! Have I scared the willies out of you? Good!

Very good advice! :thumbup:

 

[Urwumpe]

You can use the welding glasses to create a great way to observe the sun: Install them in parallel, for example with LEGO, and only observe the total reflection between the two glasses.

 

[TachyonDriver]

Not recommended. Welding goggles come in a wide variety from oxyacetylene to TIG welding, and if you don't know the difference you can do a lot of harm.

I sit corrected. Thank you.