These visual images of light and colour are called phosphenes and they're created by your own body.

这些光和颜色的视觉图像叫做光幻视，它们是由你自己的身体产生的。

Most of the time, phosphenes are harmless and temporary, but if they persist it might indicate something more serious.

多数时候，光幻视是无害的和暂时的，但是如果他们持续存在的话，这可能会预示着一些更严重的事情。

Phosphenes are one of the most common drug side effects, and an early sign of multiple sclerosis, optic nerve damage and even disease.

光幻视是最常见的药物副作用之一，也是多发性硬化症、视神经损伤甚至疾病的早期征兆。