Many people think that prescriptions for eyeglasses and contact lenses are the same and that they can be used interchangeably. After all, they both help correct your vision and help you see better, right? Unfortunately, this is not the case. If you want to wear both contact lenses and eyeglasses, you will need a separate prescription for each. Here’s why.
The Difference Between Prescriptions for Eyeglasses and Contact Lenses
Like eyeglasses prescriptions, a contact lens prescription will include the lens power required to correct astigmatism, myopia (nearsightedness) or hyperopia (farsightedness).
However, depending on the degree of your refractive error and the type of contact lenses required, your optometrist may prescribe something that may be significantly different from your eyeglass prescription.
The main reason for this is because eyeglasses will sit slightly away from your eyes, whereas contact lenses will sit directly over your eyes so two different measurements will be required. You may also find that there will be a cylinder and axis value indicated on your glasses prescription but not for your contact lenses prescription.
A contact lens prescription will also contain additional specifications that will not be present in your eyeglass prescription. These values can only be determined after a comprehensive eye exam. They include:
- The Base Curve. This measurement is for the curvature of the back of the surface of the contact lens.
- The Diameter. The lens diameter will specify the overall size of the lens and, along with the base curve, will determine the fit of the lens.
- The Brand and Material. The lens brand and material should also be specified because the lens material will have a specific degree of oxygen permeability.
- An Expiration Date. A contact lens prescription will generally be valid for one year. You will need to secure a new prescription if your old one expires.
For all your eye care needs, turn to the trusted optometrists over at Opti-Care. To schedule an appointment, please feel free to give us a call at (410) 795-8670 or, alternatively, you can request an appointment online. We treat patients residing in Marriotsville, Maryland including Westminster, MD, and its surrounding areas.