What are the functions of the Eyelids?
Functions of the Eyelids:
The eyelid makes the outer most layers, covering the eye. Because of its strategic position, the eyelid serves a very important function of acting as a physical barrier between the eye and the external environment. This barrier protects the eye from physical elements including heat, radiation, excessive light and most importantly a foreign particle (referred to as a "foreign body"), which could physically damage the delicate inner coats of the eye if the eyelids were not there. Their protective functions include blinking to remove dust particles. The eyelashes play n sensory role to detect the presence of an intruding element, which in turn initiates the protective mechanisms, i.e., blinking.
The eyelids play an important role in maintaining the health of the ocular surface and the physical position of the eye within the orbit. The significance of the lids in relation to the tear film needs to be clearly emphasised. Production of tears, reflex blinking to aid in distribution of tears, and closing of the eyelids which cause propulsion of tears in the direction of lacrimal puncta to facilitate drainage of the tears are among the most significant roles played by the eyelids. The lacrimal pump responsible for the filling and emptying of the lacrimal sac is intricately linked to the movement of the eyelids.