Are you thinking about trying contact lenses for the first time or ordering a new pair online? If you already wear glasses, you might be wondering why you need a separate prescription for contact lenses. You need a prescription because contacts are medical devices that require a proper fit, careful evaluation, and professional guidance to protect your eye health. Learn about the importance of obtaining a valid prescription for contacts and the differences between glasses and contact lens prescriptions.
Can I use my contact lens prescription for glasses?
No, your prescriptions for contact lenses and glasses are not interchangeable. While both help you see clearly, glasses and contact lenses sit in different positions relative to your eye. Glasses rest about 12 mm away from your eyes, while contacts sit directly on the surface of your eye. That difference means the lens power often needs to be adjusted for contacts.
A contact lens prescription also includes details not found in an eyeglasses prescription, such as:
- Base curve – to match the shape of your eye
- Diameter – to ensure the lens fits comfortably
- Brand and material – different lenses can vary in breathability, moisture, and how they correct your vision
- Wearing schedule – how long you can wear them each day and how often you should replace them
Without this detailed information, wearing contact lenses can lead to discomfort, blurry vision, or eye complications.
Contact lens exams are about more than your vision
Getting a contact lens prescription involves more than reading letters on an eye chart. During a contact lens exam in Waterville, Maine, our eye doctor will:
- Evaluate your cornea’s shape and health
- Check for dry eyes or allergies that might affect your comfort while wearing contact lenses
- Teach you how to insert, remove, and clean your contacts safely
- Monitor how your eyes respond to lenses with a follow-up fitting
This thorough process ensures the lenses fit properly, feel comfortable, and won’t affect your eye health.
What can go wrong without a prescription?
Wearing contacts without a prescription, or with the wrong prescription, can lead to:
- Eye infections
- Corneal scratches or ulcers
- Redness, irritation, or burning
- Worsening vision over time
It’s also illegal for sellers to provide contacts—online, in-store, or anywhere else—without verifying your prescription. That includes decorative or cosmetic lenses, even if they don’t correct your vision. Some online retailers may offer lenses without verifying a valid prescription, but this shortcut can come at the cost of your eye health.
Your eyes are worth the extra care
Contact lenses are classified as medical devices by the FDA, and like any medical device, they need to be used safely. A valid prescription from a qualified optometrist ensures that the lenses you’re wearing are the right match for your unique eyes.
If you’re interested in wearing contacts, or if it’s been a while since your last fitting, schedule an appointment with our optometrists in Waterville, Maine, today.
