I used my 6s plus at night in bed for extended periods of time without eye soreness. Switched to the XS Max last month and my eyes have been sore every morning. Could you try taping the IR emitter and see if that helps?
"Andrew Marr's History of the World is a 2012 BBC documentary television series presented by Andrew Marr that covers 70,000 years of world history from the beginning of human civilisation, as African nomadic peoples spread out around the world and settled down to become the first farmers, up to the twentieth century."