What is the function of the middle saltwater layer of tears?

The middle saltwater layer of tears, known as the aqueous layer, plays a vital role in maintaining the health and function of the eye. This layer is primarily composed of water, salts, and various proteins, and its primary function is to provide lubrication to the eye. This lubrication is crucial as it helps to ensure smooth movement of the eyelids over the surface of the eye, which is important for comfort and vision.

Additionally, while the aqueous layer does have a role in helping to flush away foreign particles and debris from the surface of the eye, its function of lubrication is considered more essential. The tears are also responsible for maintaining a healthy environment for the cornea, providing necessary nutrients, and serving an immune function by containing proteins that combat infection.

Understanding the principal function of the aqueous layer as lubrication helps clarify its significance in overall eye health and comfort, distinguishing it from other functions like nourishing the cornea or regulating eye pressure.