What causes morning eye mucus?

Morning eye mucus, often referred to as "sleep" or eye discharge, is primarily caused by the accumulation of tears, oil, and debris that collect in the corners of the eyes during sleep. During the night, the eyes produce fewer tears, leading to a build-up of mucus and other particles. This discharge can also be a response to irritation or inflammation from allergens, infections, or dry eyes. In most cases, it's normal, but persistent or unusual discharge may warrant a visit to an eye care professional.