Dry Eye And Tears Are Not The Same

Introduction

Dry eye and tears are not the same. You might know that, but did you know that your tears are made up of three layers? Or that your ocular surface is a complex ecosystem? Or that there’s more to dry eye than just “not enough tears”? We’ve got answers!

Tear film is made up of three layers

The tear film is made up of three layers, the lipid layer, aqueous layer and mucin layer. This multi-layered structure is important to how our eyes function. The top-most layer (lipid), which acts as an oily barrier against bacteria and other particles that could potentially cause harm to our cornea, forms when we blink. As we blink we temporarily remove this lipid layer so it can be replaced by the next layer down: an aqueous portion which contains watery tears (tears are actually mostly water). The third part of your tear film is mucus—it helps keep all those other layers together.

Mucus naturally occurs in many animals’ bodies including humans’ noses; it’s a sticky substance that helps us breathe and eat food without choking on it! When you’re sick with a cold or allergies there tends to be more mucus than usual though…and sometimes even before that happens due to dry weather conditions like those found during winter months here in Canada where I live.”

The ocular surface is a complex ecosystem

While tears are made up primarily of water, they are not just water. Tears actually contain a complex mixture of compounds that help protect the eyes from bacteria and viruses as well as nourish the cornea. There are even compounds in tears that help to regulate your body’s temperature.

The mucus layer is just one component of tears; it helps to lubricate the eye and prevent damage from debris or foreign bodies. This mucus can also trap dust particles before they reach the cornea. Mucous membranes produce secretions such as antibodies that neutralize harmful viruses, bacteria, parasites and other pathogens—so by keeping them healthy you’re protecting your ocular surface too!

Tears are not like rice

So, here are some facts about tears.

Tear production is not constant. We make more when we’re sleeping and less when we’re active.
Tears aren’t like water or oil. They can’t be measured with a ruler or weighed on a scale because they don’t have an exact volume or density (water has a density of 1 kilogram per liter). That means that if you use something like this to measure your tear output over time, you will get different numbers every time—and even if it were an accurate number, it’s still not a good indicator of how much you’ve been crying! Imagine trying to measure how much water has passed through your showerhead over an hour by holding up some sort of measuring device in front of the spray stream: there’s no way that would work well enough for any useful data collection purposes…

You can have “good” tears and still have dry eye

This is because your tears can be good and still dry.

You can have “good” tears and still have dry eye.

Tears are not like rice, where a lack of water makes them turn into mush. While tear quality does play a role in dry eye, it’s just one piece of the puzzle—and not even the biggest one at that. The tear film is made up of three layers: an outer lipid layer, an inner mucin layer, and a middle aqueous layer (see diagram above). These layers work together to provide what we call “wetness” or lubrication for our eyes by acting as natural cleansers that remove foreign objects like dust or pollen from the surface of our eyes; they also help to keep our corneas clear so we don’t have to blink constantly when we’re trying to focus on something up close!