Your tear film is crucial for both good vision and ocular comfort. The tear film is actually composed of three different layers. The innermost layer is made of mucous that helps the tears “stick” to the eye. The middle layer is composed of an aqueous water layer. The surface layer is composed of lipid (oil) that keeps the tear film from evaporating too quickly. This oil is produced by the meibomian glands. For the health of the tear film, both the amount of tears AND the composition of the tear film is important. Rewetting drops usually replace only the middle aqueous layer, while warm compresses can improve the oil production from the meibomian glands. Restasis eye drops may increase the eye’s production of tears in certain cases, while punctal plugs keep the tears from draining away too quickly. The tear film is where the majority of light focusing occurs. If this surface has any irregularity to it (from dry eye or excessive tearing) the vision will be severely affected.