Alright, we have our first official response from the Square Enix Support Center:
Dear -------,
Thank you for contacting the Square Enix Support Centre.
We are sorry to hear that you have experienced this situation and we thank you for providing us with this feedback.
We have passed on the information to the relevant team. While you will not receive a direct response, please know your feedback will be read and taken into consideration. Please keep an eye on any updates or announcements that may be related to this topic.
Not sure how much of this response is stock, but the fact that they've (seemingly) acknowledged the issue's existence is at least something. If there's still someone out there who hasn't yet made a support ticket about their eye strain problems, please do so now. Every single one matters in getting the devs to fix this issue.
If possible, be sure to also provide them with a link to this forum post, so as to show them that it's no isolated incident.