Light weight headphones

I forgot to mention, the Sennheiser HD800 are also super comfortable, and more refined sounding than the 600 series variants.  I haven't heard the HD800s, which are supposed to be tuned a little "darker" than the HD800, but the HD800 are a different sound signature than the Audeze house sound, more neutral and detailed.  Some like it, some find it a little too "analytical".  I think they are great sounding headphones.

Meze Empyrean. I even pass out in bed with them on. Very light an comfortable.

ERA-1s are 2/3 the weight.
Might not be light enough for you.

Out of the dozen I own the best to have on your head is the AKG 240 .
Light with good sound , not much money, and they still sell well 
after 30 years

On my head right now .

I have both the Audeze LCD-XC and Stax 009s. Both are heavy, which is the main reason for my short listening sessions. If I could find phones that sounded as good but were lighter, I'd be interested. I have owned lighter headphones but I'm just not comfortable with the tradeoff in sound quality.