Light weight headphones

The most comfortable headphones I own (I have about 10 or 12) are my Sennheiser / Drop HD6XX - https://drop.com/buy/massdrop-sennheiser-hd6xx.  Changing out the earpads can make them even more comfortable.  Not just comfortable, but lots of bang for the buck.  Maybe not quite on the same level as the LCD-X in terms of detail and bass quality/quantity (I have the LCD-XC, but haven't heard the LCD-X), but very easy to listen to.

If your budget is higher and you like the Audeze sound, check out the Sony MDR-Z1R.  They give my LCD-4 a run for the money in terms of bass and sound quality and are a lot more comfortable.

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 .