That’s the question [Kathy] asked when she built this LED matrix light pen project. It looks simple enough – a 64-LED matrix illuminates as the pen draws shapes.

The LED Moonlight pen works like a pen, but has a light on the tip so you can read what you write, even in movie theatres, back alleys, and inside a patient’s abdomen.

LED Pen Lights Streamlight’s FiberWrap fiberglass polymer pen lights come in four high-intensity LED colors. The red, green, white and blue PolyStylus pen lights feature a 5-mm LED designed for ...

Best Affordable Teeth Whitening Pen + LED Light Kit. SmileDirectClub SmileDirectClub Teeth Whitening Kit with LED Light. Now 12% Off. $34 $30 at Amazon. Pros. Cons. Requires LED light; ...