Certified Ophthalmic Technician (COT) Practice Test 2026 - Free COT Practice Questions and Study Guide

The component of the tear film that plays a significant role in lubrication is primarily mucins. Mucins are glycoproteins found in the mucus layer of the tear film and are crucial for maintaining a stable tear film on the ocular surface. They have a unique structure that allows them to trap water and create a gel-like consistency, which helps to facilitate smooth movement of the eyelid over the eye during blinking. This reduces friction and maintains comfort and health of the ocular surface.

Mucins also contribute to the overall stability of the tear film by anchoring it to the corneal epithelium, which is essential for the lubrication function. Without sufficient mucin, the tear film would be less effective in preventing corneal dryness and irritation, leading to discomfort.

While oils, electrolytes, and water all contribute to various aspects of tear film composition and function, it is the mucins that are specifically responsible for the lubrication required during eyelid movement.