Interesting question……
I’m guessing you’re talking about the free 3D glasses you get from the movie theaters when you go to see a 3D movie.
I know it’s a little dark in the theater,
but if you read the package your 3D glasses came in,
the answer would be NO.
Let’s all read this WARNING label together:

WARNING:
NOT SAFE FOR USE AS SUNGLASSES
These glasses do not screen ultraviolet light. Wearing them as sunglasses will not protect your eyes. Use only in the theater. Keep out of reach of children under 3.
Huh, obviously, they don’t want you wearing those outside.
Maybe they seriously care about your eyes or maybe they just want you to leave them there in the recycling box.
Hard to tell.
Sometimes I think some of these companies put ridiculous warnings on their labels for entertainment purposes.
Like the guy in the label making department always wanted to be a comedian or something.
And you know exactly what labels I’m talking about,
take the Superman Costume label:
Warning:
This clothing does not enable flight or super strength.
Or
the hair dryer label warning us to not use while sleeping
You think?
Here’s a couple more labels worth noting:

Seriously, who’s putting people in washing machines?
Wow….
make sure your dog skips happy hour at the local bar,
& doesn’t drive the car….
or operate dangerous machinery while he’s on these meds
I want to say….
they think we’re morons.
Are they protecting themselves from being sued?
Who knows.
But, you have to wonder if the reason they are writing these warnings
is, because someone has actually done it.
Kind of scary.
Anyway….I’m getting off track again…
we’re talking about wearing 3D glasses as sunglasses……
First, let’s get a little history on 3D or 3Dimensonal Glasses:

3D glasses were popular in the 1950’s. Although, they were actually invented in 1922.
They have gone in and out of popularity for decades.
Lately, we’re seeing more 3D movies at the theaters
and they’ve even come to our home TV’s, are on DVD
and have been incorporated into video games.
Technology….got to love it.
This is how 3D works:
3D functions on a binocular vision system, which basically means
it’s vision that incorporates images from both eyes simultaneously. The slight differences between the two images—seen from slightly different positions—make it possible to perceive distances between objects in what is known as depth perception.
Here is a familiar pair of 3D glasses, which are still used today.

The red and green or red and blue paper 3D glasses were used to view many older 3-D movies. The way this works is two images are displayed on the screen, one in red and the other in blue (or green). The filters on the glasses allow only one image to enter each eye, and your brain does the rest. They make the movie or television show you’re watching look like it’s happening right in front of you. With objects flying off the screen and in your direction, you feel part of the movie. Although, you can’t really have a good quality “color” movie when you are using color to provide the separation, so the image quality is not nearly as good as with the newer polarized system.
At Disney World, Universal Studios and other 3D venues, the preferred method uses polarized lenses because they allow color viewing. This is where two synchronized projectors project two respective views onto the screen, each with a different polarization. The glasses allow only one of the images into each eye because they contain lenses with different polarization.

These plastic polarized 3D“Clark Kent” looking glasses have for the most part, replaced the older red and blue 3D glasses and look very similar to a regular pair of sunglasses…..
which I guess brings us back to the original question.
Can you wear your 3D glasses as sunglasses?
Well, I actually tried a pair on,
and surprisingly, I saw clearly out of them….
but then I looked in the mirror…and NO….
I would definitely NOT wear these in the daylight.
First, my eyes looked goofy like an image in a trick mirror….
& secondly, they were big, bulky, they sat weirdly high on my face, they weren’t dark enough
and honestly, they just looked ridiculous.
So…..
I will stick with the manufacturers warning
& NOT wear these out of the theater…
but, for more reasons than possible eye damage.
Thanks for the question