Over 30 years ago (IE, before I married my DH), there were a couple of very good scientific studies done showing that the quality of lighting makes a HUGE difference in workplace productivity and in classroom learning. More recently (2005, maybe?) I saw a piece on Simply Quilts with an MD talking about sewing room ergonomics (she'd written a book on the subject). What most struck me about her comments was the regular, predictable, dramatic increase in light required as we age. She expressed it as % increase required. I can't recall the exact #s, but it went something like ...age 60 requires 70% more light than age 20. Get LOTS of lights and leave off the ones you don't need YET.