This is a super easy life hack that you can do with only a rubber band and a styrofoam cup. I was having problems with the super bright LED light glaring off my desk and it ended up giving me headaches. So, I put a styrofoam cup on it. It doesn't make it any dimmer it just spreads the light out rather than having it in one focussed beam. It helps a great deal. No more headaches. It also looks pretty cool.
Warning: Do not try this on any light that produces heat. It will start a fire. Use common sense. LEDs work the best because they don't make a lot of excessive heat.
Step 1: Installing It
Slide the rubber band under the base of the cup and then stretch it to the top and let go.