If you’re new to the world of contact lenses, you might wonder how such a small, thin disc stays on your eye. The mechanics behind a stable contact lens are actually quite simple and involve the natural design of your eye.
Contact lenses are a partnership between optics and the anatomy of your eye. A contact lens stays in place because it’s designed to fit the curve of your eye and float on your natural tear film. This creates a gentle, comfortable suction that keeps your vision clear and your lens secure throughout the day.
The Science Behind a Contact Lens & Your Eye
Your eye’s natural shape and the thin layer of moisture that covers them combine to help keep your contact lenses in place.
How Your Cornea Creates a Natural Fit
The cornea is the clear, dome-shaped outer layer at the front of your eye. The cornea curves outward, and contact lenses are manufactured to match this curve. The resulting fit helps your lenses settle over your cornea and remain centered, in place.
The Role of Tear Film
Your eyes are coated in a thin, protective layer of tears called the tear film. A contact lens doesn’t sit directly on your eyeball—it actually floats on top of this tear film. The moisture creates surface tension, which produces a gentle suction that holds the lens in place and allows it to move smoothly when you blink.
A Custom Fit for Your Vision Needs
No two eyes are exactly alike, so contact lenses come in many shapes and sizes to accommodate differences. A prescription for contacts includes much more than just your corrective power—it also specifies the measurements for properly fitting lenses. We can perform a detailed fitting to determine the right lens for you.
Why Measurements Matter
During a professional contact lens fitting, an eye care professional measures the curve and diameter of your cornea. These measurements help make sure that your contact lenses aren’t too tight or too loose on your eye. A lens that fits well stays in place, feels comfortable, and provides clear vision.
Different Lenses for Different Eyes
Contact lenses are designed to correct various refractive errors by focusing light correctly onto your retina. Depending on your needs, your doctor may recommend different options from the many types of contact lenses available. For example, some common lens types include:
- Spherical lenses that correct nearsightedness or farsightedness.
- Multifocal lenses that help with clear vision at different distances.
How Contacts for Astigmatism Work
If you have astigmatism, your cornea is shaped more like a football than a sphere. This irregularity often requires a specialty contact lens.
Toric Lenses & Their Unique Design
Toric lenses are specifically made to correct astigmatism. They often have a small weight at the bottom or are shaped differently in certain zones to prevent rotation. This design uses gravity and the natural pressure from your eyelids when you blink to keep the lens stable.
The Importance of Lens Orientation
For a toric lens to provide clear vision, it must sit on your eye at a precise angle. If it does move, these same features help it quickly return to the correct spot after you blink.
Why Your Contacts Sometimes Move Out of Place
Even with a perfect fit, a contact lens can occasionally shift. This is usually temporary and easy to correct without much trouble. Common factors like dry eyes, rubbing your eye, or improperly handling your lenses can cause it to move off-center.
Common Reasons for Contact Lenses to Shift
A lens might move if your eyes become unusually dry or watery. Blinking a few times is often enough to help your tear film re-center it. If your lenses frequently move, this could be a sign of an improper fit.
How to Reposition a Slipped Lens
If a lens moves off-center, you can typically guide it back into place with your finger. First, close your eye and gently massage your eyelid to slide the lens back to the middle. Alternatively, you can wash your hands thoroughly and use your fingertip to gently slide the visible lens back over your cornea.
Can a Contact Get Lost in Your Eye?
A frequent worry for new contact lens wearers is the idea of a lens getting permanently stuck or lost behind their eye. The good news is that this is anatomically impossible. A thin, strong membrane called the conjunctiva connects your eyelid to your eyeball, stopping anything from getting behind it.
What to Do If You Can’t Find Your Lens
Sometimes a soft lens can fold or move under your upper eyelid. This might feel uncomfortable. You can often find the lens by looking in a mirror, pulling up your eyelid, and looking down. Adding a few rewetting drops can also help it move to a spot where you can see it and remove it safely.
If you are ever unable to remove a lens or experience significant pain, it’s important to seek prompt emergency eye care.
Get a Contact Lens Exam & Fitting Today
At Total Vision in Huntington Beach, our team is here to help you find a comfortable and effective vision solution. A professional contact lens exam is the first step toward clear and comfortable wear. Schedule an appointment with us to explore your contact lens options.
