iPhone 12pro Max causing severe eye strain

I had a same problem with my iphone x. Problem could be that you are switching screens too often like (pc, phone, tablet). Also try distance 50 cm phone away from your face. Also try to turn on night shift and lower the brightness

There is nothing special about iPhone 12 Max screen compared to other phones,

I would suggest you consult your doctor/Optician

I suggest that you spend less time on the screen and if the problem continues consult your eye care provider.

I haven't noticed anything out of the ordinary. You get that only when using the iPhone?

Do you have eye pain?

OLED displays are special.

OLED displays are pretty common on phones, and have been for quite some time

The 11 Pro Max was Apple's first and all the 12's have it.

We are getting off-topic, but:

No, the first Apple phone to have it was iPhone X back in 2017.

After that the iPhone Xs and Max, iPhone 11 Pro and Max, and in 2020 all the 12's had it.