I use an LED headlight, remove the elastic band, and Velcro it to the visor cover. There are many available, and I don't even know the brand or model I'm using now. It has red, blue, and white LEDs, but the first on is red, and when I'm done I just loosen the screw-on battery cap, and it goes off without switching to the other lights. It has a diffraction lens, works on one AA battery, and does a good job for me. I've modified others to use green LEDs, with work OK. There are many that use multiple AAA batteries, but are harder to turn off without cycling through all the colors.