might he be fantasizing? I love looking at my wife when having sex. Did you ask him why he looks every place except at you?
I don't think it's unusual or abnormal. After all, everyone has their own unique way of doing things... my boyfriend closes his eyes during intimacy. And, this all could be tied into that "fantasizing" aspect that gymdandee mentioned.
I frequently will have to look away from my wife to prolong things..seeing certain parts of her body moving around really does it for me to I need to be distracted at times.
Jim