K-Moss Ive had phone 2000hz honor and it killed my eyes and I've had 240 Hz from Xperia and it was heaven. I wouldn't look entirely at HZ there are more factors at play. It seems modulation in respect to screen refresh. Also ltpo seems a culprit. https://www.reddit.com/r/PWM_Sensitive/comments/1n9w9qb/need_advice_for_next_phone/
Donux K-Moss Could be also that different people react to different PWMs differently. In fact some PWMs can induce calming effect rather than stress and eye strain in my opinion.