Eye health resource
Important Facts About Contact Lens Prescriptions
A contact lens prescription is different from an eyeglass prescription because contact lenses are medical devices fitted to the eye. Learn what the prescription includes, when it is released, and why cosmetic contacts also require one.
Reviewed for accuracy by Justin Bazan, OD on .
A contact lens prescription is not simply an eyeglass prescription written on a different form. Contact lenses sit directly on the eye, so the doctor must determine not only the optical power but also which specific lens design, material, size, and fit work safely and effectively for your eyes.
Why Is a Contact Lens Prescription Different From a Glasses Prescription?
An eyeglass prescription describes the lens power needed in front of the eyes. A contact lens prescription also identifies the contact lens that was actually fitted and evaluated on the eye.
Depending on the lens, the finalized prescription may include:
- lens power;
- manufacturer and brand or material/design;
- base curve or another fitting designation;
- diameter when applicable;
- cylinder and axis for toric lenses;
- add power or design information for multifocal lenses; and
- other parameters required for a specialty lens.
That is why two lenses with the same printed power are not automatically interchangeable.
What Happens During a Contact Lens Fitting?
A contact lens fitting may include corneal and other measurements, discussion of lens type and wearing goals, diagnostic lenses, evaluation of how the lens centers and moves, vision testing through the lens, and assessment of the ocular surface.
Some straightforward soft-lens fittings can be finalized quickly. Toric, multifocal, monovision, scleral, GP/RGP, Ortho-K, or other specialty fittings may require additional visits or lens changes before the prescription is final.
When Do I Receive My Contact Lens Prescription?
Under the federal Contact Lens Rule, the prescriber must provide a copy of the contact lens prescription when the fitting is complete, even if the patient does not ask for it.
You are not required to purchase contact lenses from Park Slope Eye in order to receive the finalized prescription.
We do appreciate the opportunity to provide a quote because we often offer very competitive contact-lens pricing and contact-lens sales are an important part of supporting our independent practice, but the purchase decision is yours.
How Long Is a Contact Lens Prescription Valid?
Federal rules generally require a contact lens prescription to remain valid for at least one year unless there is a legitimate, documented medical reason for a shorter expiration period. If state law requires a longer minimum period, the longer period applies.
The expiration date does not mean a lens becomes unsafe at midnight on that date. It means a new prescription cannot be filled after expiration without an updated prescription. Regular follow-up is important because the prescription, corneal health, tear film, lens fit, or wearing habits can change even when vision still seems clear.
Do Decorative or Colored Contacts Need a Prescription?
Yes. Decorative, costume, and colored contacts are still medical devices in the United States, even when they have no vision-correcting power.
Buying decorative lenses without a proper prescription and fitting can expose the eye to poor fit, corneal abrasion, infection, scarring, and vision loss. Never share contact lenses with another person.
Can I Substitute Another Brand With the Same Power?
Not automatically. Contact lens brands can differ in material, geometry, diameter, base curve, edge design, optics, and surface characteristics. A lens with the same power may fit or perform differently on the eye.
If you want to change brands because of comfort, cost, availability, allergy, dryness, or convenience, a contact lens evaluation is the appropriate way to determine whether another lens is suitable.
Contact Lens Safety Still Matters After the Prescription Is Final
Follow the prescribed replacement and wearing schedule. Daily disposable lenses are designed for one day of wear and should not be cleaned and reused. Reusable lenses require the recommended cleaning and disinfection system.
Keep lenses away from tap water, pools, hot tubs, and showers whenever possible. Do not “top off” old disinfecting solution. Sleeping in lenses increases infection risk unless overnight wear is specifically part of the prescribed lens treatment, such as properly managed Ortho-K.
Pain, marked redness, light sensitivity, discharge, or reduced vision in a contact-lens wearer warrants prompt evaluation.
Contact Lens Prescriptions at Park Slope Eye
Park Slope Eye fits soft spherical, toric, multifocal, monovision, scleral, GP/RGP, Ortho-K, and other specialty contact lenses. Contact-lens orders are paid in full before ordering, and reorders are handled by email rather than through an online store.
For current fitting and self-pay information, see our Insurance, Fees & Patient FAQs, or book an appointment.
Originally published . Substantially updated .