Actually, I went on to a 13 Pro Max and got eyestrain. It was so bad I was going blind. So this was honestly not that bad. It only happened once and if the 11 had 5G, I wouldn't have upgraded.so ever since you got the phone,the infra red suddenly became stronger? perhaps the infrared is faulty?
Actually I moved on the 13 Pro Max but it was so bad I was going blind. Not from that red light here but from PWM eye strain.I'm not saying that it's out of the question for some eyes out there to see the red light, and if the only thing in your life that has changed is the phone, then I'd say you might be onto something, but I would ask your eye doctor, or take it to an apple store and have them look at it. The phone could have been hit just right to knock something loose or something like that.