Augenlider

Augenlider are the movable folds of skin and muscle that cover and protect the eye. They play a crucial role in maintaining ocular health by spreading tears across the surface of the eye, thus lubricating it and washing away debris. The eyelids also help to regulate the amount of light entering the eye, shielding it from bright light and protecting it from foreign objects such as dust and sand.

There are two eyelids: the upper eyelid and the lower eyelid. Both are composed of several layers, including skin, subcutaneous tissue, muscle (orbicularis oculi for closing and levator palpebrae superioris for lifting the upper lid), tarsal plates (cartilaginous structures that provide rigidity), and the conjunctiva, a thin membrane lining the inner surface of the eyelid and the front of the eyeball. Eyelashes, located at the edges of the eyelids, offer an additional layer of protection by catching small particles.

The blinking reflex, an involuntary rapid closing and opening of the eyelids, is essential for keeping the eye moist and clean. Voluntary blinking can be consciously controlled for various purposes, such as signaling or expressing emotion. Problems with eyelid function can lead to various conditions, including dryness, irritation, infection, and visual impairment.