About Contact Lens Calculator
Our mission is to provide accurate prescription conversions and helpful resources for contact lens users.
Our Story
Contact Lens Calculator began with a simple goal: to make it easier for people to convert their glasses prescriptions to contact lenses accurately.
Contact Lens Calculator is maintained by an independent publisher. It exists because many people order contact lenses online without fully understanding how to convert their prescriptions correctly.
This led to incorrect orders, wasted money, and even potential eye health issues. We set out to create a free, accessible tool that would help people make informed decisions about their contact lenses.
The calculators are free and need no account. They apply the standard vertex-distance and spherical-equivalent formulas, stated on each page, and every result says it is a starting point for a fitting, not a substitute for one.
Our Values
The principles that guide our work and commitment to contact lens users.
Accuracy
We use scientifically validated formulas to ensure the most precise prescription conversions possible, taking into account factors like vertex distance and lens materials.
Accessibility
We believe that everyone should have access to tools that help them make informed decisions about their vision care, which is why our calculator is free to use and designed to be user-friendly.
Education
We're committed to providing evidence-based information about contact lenses and eye health to help users understand their vision care options and make the best choices for their needs.
Contact Us
Have a question, suggestion, or just want to say hello? We'd love to hear from you.
One route
The form on this page is the only way to reach the site; there is no mailbox and no phone line. A correction with the page address and a source is checked first.
Send Us a Message
Corrections, questions about a converter, or a broken page.
Frequently Asked Questions
Answers to common questions about our calculator and contact lenses.
Is your calculator's conversion accurate?
Our calculator uses scientifically validated formulas based on optical principles to convert glasses prescriptions to contact lens prescriptions. While the calculations are accurate, every eye is unique, and your eye care professional may make additional adjustments based on your specific needs.
Do I still need to see an eye doctor?
Yes, absolutely. Our calculator provides an estimated conversion, but a proper contact lens fitting by an eye care professional is essential. Contact lenses sit directly on your eye and require professional fitting to ensure proper movement, oxygen transmission, and comfort.
How often should I update my contact lens prescription?
In most cases, contact lens prescriptions expire after one year. Regular check-ups are important not only for vision correction but also to monitor eye health, as contact lens wear can sometimes lead to complications if not properly managed.
Is your calculator free to use?
Yes, our calculator is completely free to use. We believe that everyone should have access to tools that help them make informed decisions about their vision care. We sustain our site through affiliate partnerships with reputable contact lens retailers.
Ready to Convert Your Prescription?
Use our free calculator to get an accurate contact lens prescription conversion.