Tear film consists of lipid layer, aqueous layer, and mucin. Water loss and blockage of the meibomian glands lead to eye fatigue, dryness, blurred vision. Anatomical structure of eye, 3D animation.

The Composition of Cervical Mucus ​Cervical mucus is a hydrogel composed of water, glycoproteins (mucins), enzymes, and salts. Its consistency changes throughout the menstrual cycle. ​Non-Ovulatory Phase: For most of the cycle, the mucus is thick, sticky, and forms a dense mesh. This creates a physical barrier that is nearly impenetrable to sperm, preventing them from entering the uterus when fertilization is not possible. ​Ovulatory Phase: Around the time of ovulation, high estrogen levels caus