Wattage Best For...
Use a 40- to 60-watt bulb. To prevent shadows, the lamp should be between your head and the page. A lamp with an opaque shade, like a metal reading lamp, cuts glare.
Staring at a Computer
To prevent eye fatigue, keep the light in the room no brighter than the screen. Sixty watts in a desk lamp, supplemented by soft, ambient light (from outside or overhead) will do the trick.
Putting on Makeup
You’ll need 60 to 80 watts of light. So a 40-watt bulb in each of a pair of sconces or three to four 25-watt bulbs above the vanity work well. Add the overhead if you need more.