If you had an array of high power addressable LEDs, how would you project them onto a wall? Perhaps you’d use a Fresnel lens, or maybe an individual lens on the top of each. [Joo] faced this problem ...

Light-emitting diodes (LEDs) can cause headaches or trigger migraine in some people. However, some research suggests green LEDs may help with migraine symptoms and headaches. Exposure to LEDs occurs ...