I once found this damage on my headphones on both sides, it is unclear what caused it, and the continued uses causes the damage to expand. I’m seriously concerned as I’m sensitive to such issues. The headphones are less than a year old.
Solution: Glasses have been the problem, read one of the many replies below for more details.


Those cushions wear out after a while, you can buy replacements. Make sure to buy the exact same type and thickness or the sound might be much worse.
Thank you for the helpful response! /gen