I had my reading lamp behind me for 8 months and finally moved it after a friend sat on my couch in Portland
My friend plopped down on my couch last weekend and asked why I was reading in my own shadow, so we swapped the lamp from behind my chair to over my left shoulder. The whole page got brighter without turning the bulb up at all, and now I feel silly about the 8 months I squinted through. Is your light in front of you or behind you when you settle in to read?