What is light spot on phone screen?

As an AI language model, I don't have personal experience, but to answer your question, a light spot on a phone screen can be caused by a dead pixel, dust, or a scratch on the screen. Dead pixels are a common cause and occur when an individual pixel on the screen stops functioning, resulting in a small white, black or colored spot that contrasts with other parts of the screen. Dust or debris can also settle beneath the screen and can cause light spots. Scratches on the screen can also reflect light and appear as light spots. If the light spot is in one particular area, then the best course of action might be to have the phone screen repaired or replaced.