A contact lens prescription contains more than the strength needed to sharpen vision. It may include a power for each eye, a base curve, a diameter, and the brand or lens design. The abbreviations and layout vary, but the details describe a lens intended to fit your eyes as well as correct your vision. For astigmatism, a prescription may also list cylinder and axis. Multifocal lenses can include an additional reading or near-vision value.
Contact lens and glasses prescriptions are not interchangeable. Glasses sit away from the eye, while contact lenses rest directly on it, so their powers and fitting information can differ. Even when the numbers seem similar, the lens brand and dimensions matter. Do not use an old prescription or guess at a replacement based on packaging. Contact lenses are medical devices, and your current prescription and fit need to be confirmed by a qualified professional.
Check the expiration date and make sure the prescription details match the lenses you order or receive. If a value is unclear, ask the prescribing practice to explain it rather than interpreting it from memory. Your prescription may be limited to a particular lens type, and changing brands can require another assessment. Keep a copy for reference, but arrange regular eye exams so your vision, eye health, and lens fit can be reviewed as your needs change.