Go Direct and Old Acro are absolutely correct, Randolph Aviators all the way.
They are Milspec and standard issue for the US military and NASA.
See here-
Sunglasses | Randolph Engineering :: Sunglasses and Shooting Eyewear
The specs are listed next to the Aviator pics.
I see they are $199 on Randolph US website. I got them cheaper than from Randolph from a US store where I flew and at the time they were about $70-75USD IIRC.
They are real sun "glasses" with mineral crown glass lenses and are bloody tough as nails!!
I had mine for nearly 20 yrs and not a scratch on the lenses despite hard impacts with corner metal airplane parts direct onto the lenses, once or twice with me wearing them,(ouch) and just after I got them they got flung off my face at high speed onto steel decking when a high speed fun ride unexpectedly went upside down.
I expected them to be in a million pieces but the attendant brought them over and not a scratch anywhere, I was absolutely stunned.
Just looked at them now real closely as I type this and cannot even see any very fine scratches in the lenses like you get over time with polycarbonate.
So long as you dont lose them they will probably be the last sunglasses you ever need to buy.