Why do you see stars or moving dots after prevent yourself from sneezing out loud?

You are not seeing actual stars or moving dots. You are experiencing a visual phenomenon known as phosphenes.

Phosphenes are flashes, streaks, or spots of light that you perceive despite the absence of any external light source. They are the result of the mechanical or electrical stimulation of the retina, the light-sensitive layer at the back of the eye.

When you prevent yourself from sneezing, you create a sudden and intense increase in pressure inside the skull and eyes. This pressure can stimulate the retina, triggering phosphenes. The dots or streaks you see are caused by the activation of different groups of photoreceptor cells in the retina.

The effect is usually harmless and temporary, disappearing once the pressure is released. However, if you experience persistent visual disturbances, it's important to see an eye doctor to rule out any underlying medical conditions.