Help! My Eyes Are Suffocating!
It may sound strange, but your eyes need to breathe. When you think about the parts of your body that require oxygen to function properly, you realize that a constant oxygen supply makes sense. Usually, oxygen is delivered to the rest of our body through our network of blood vessels. Your eyes are a little different, because the cornea is one of two organs that does not get its oxygen from this network of blood vessels (the second is your lens, which is also in your eye!). Instead, your corneas receive oxygen directly from the air. The oxygen dissolves into your tears and then permeates into the corneal tissue to keep it functioning properly and staying healthy. This is why we say your eyes need to breathe!
Our eyes are pretty good at breathing naturally, but when you wear a contact lens that is not breathable, you directly limit the oxygen supply to the cornea. Your eyes can start to look red almost all the time and they can feel irritated. When we evaluate your eyes under the microscope, we can start to see the growth of blood vessels into the cornea. This is called corneal neovascularization, and it’s a sign that the eyes are trying to get oxygen through a different means. The body is amazing, but that is not what we want it to do and this is not the news we want to deliver.
There are a few factors to consider when a contact lens is deemed not breathable and this can actually vary from person to person. Contact lenses made of hydrogel materials with lower water content are generally less breathable for everyone. These contact lenses do not allow for great oxygen transmission through the contact lens to the cornea. It can become even worse when the contact lens is too tight for your eye or when you have a high prescription. When a contact lens is tight, it reduces the flow of your tears underneath the contact lens, when in fact, your tears are supposed to help deliver oxygen from the air to the cornea. If we talk about a thicker contact lens, it can vary from design and your prescription. Contact lenses for high prescriptions are thicker, just like eyeglasses for high prescriptions are thicker and a thicker contact lens means it is harder for the oxygen to get past the material.
To address these issues, it can be as simple as switching to a contact lens made of a silicone hydrogel material, which is more oxygen permeable. Sometimes, it’s not as easy. It can take your eyes a while to adjust to a new material. Either way, we are always here to help and make sure your eyes are healthy and your contact lenses comfortable.