are the protecting and supporting structures (adnexa) of the eye, including the eyebrow, eyelids, and lacrimal apparatus.

The eyebrows, eyelids, eyelashes, lacrimal gland and drainage apparatus all play a crucial role with regards to globe protection, lubrication, and minimizing the risk of ocular infection.

The main function is to prevent sweat, water, and other debris falling into the eye, but they are also important to human communication and facial expressions.

They function to heighten protection of the eye by catching dust and debris via blinking, and to regulate evaporation of the tear film of the cornea.

Eyelashes are also important in human society and beauty standards, as prominent lashes draw attention to the eyes and thus are a universally desirable facial feature.