How to Choose the Right Base Curve for Your Colored Contacts

Quick Answer

To choose the right base curve for your colored contacts, always follow your eye care professional's prescription or fitting measurement. If you don't know your base curve, most FreshTone lenses use a standard 8.6 mm curve, but you should verify with an eye exam before ordering.

When shopping for colored contacts, you might focus on color and pattern, but the base curve is just as important. The base curve is the curvature of the lens that matches your eye's shape. A proper base curve ensures the lens sits comfortably and moves correctly on your eye.

Many people wonder about the difference between 8.6 and 8.7 base curves. In this guide, we'll explain what base curve means, how to find yours, and how to use a contact lens base curve chart to make an informed choice.

What Is Base Curve and Why Does It Matter?

The base curve of a contact lens is the measurement of the back surface curvature, typically expressed in millimeters. A steeper curve has a smaller number (like 8.4), while a flatter curve has a larger number (like 8.8). Most standard lenses use an 8.6 mm base curve, which fits a majority of eyes.

If the base curve is too steep, the lens may pinch and cause discomfort. If it's too flat, the lens may move too much, leading to dryness or blurred vision. That's why matching the base curve to your eye's shape is crucial for both comfort and eye health.

• Never guess your base curve; get it measured by an eye care professional.
• If you already wear contacts, check the box or your prescription for the base curve value.

How to Find Your Base Curve

Your base curve is determined during a contact lens fitting. An eye doctor uses a keratometer to measure the curvature of your cornea. This measurement is then used to select a lens with a matching base curve. It's not something you can measure at home.

Once you have your base curve, you can use a contact lens base curve chart to see which lenses are compatible. Most colored contacts, including FreshTone, offer a standard 8.6 mm base curve. If your prescription shows a different value, you may need to look for lenses that offer that specific curve.

• If you don't know your base curve, schedule an eye exam before ordering colored contacts.
• Keep your contact lens prescription up to date; it includes base curve and diameter.

Base Curve 8.6 vs 8.7: What's the Difference?

The difference between 8.6 and 8.7 is only 0.1 mm, which is very small. For most people, this difference is negligible and both curves will fit comfortably. However, if you have a flatter cornea, an 8.7 base curve might provide a slightly better fit, reducing edge lift and improving comfort.

Conversely, if you have a steeper cornea, an 8.6 curve may be more appropriate. It's important to remember that these are just guidelines. Your eye care professional's recommendation should always take precedence. If you're between sizes, they may suggest a trial lens to see which feels better.

• Don't stress over 0.1 mm differences; comfort and professional guidance matter more.
• If you experience discomfort, ask your eye doctor to re-evaluate your base curve.

Using a Contact Lens Base Curve Chart

A contact lens base curve chart lists the base curve options for different lens brands and models. It helps you quickly see which lenses are available in your size. For example, many FreshTone lenses come in an 8.6 mm base curve, which is the most common size.

When using a chart, also check the diameter. The diameter is the width of the lens, and it works together with the base curve to ensure proper fit. A lens with too small a diameter may not cover your iris fully, while too large may cause irritation.

• Always match both base curve and diameter to your eye measurements.
• If a lens isn't available in your size, ask your eye care professional for alternatives.

Decision Rules for Choosing Base Curve

• If you know your base curve from a prescription: Select a lens that matches that exact base curve. If your prescription says 8.6, choose lenses with an 8.6 base curve. Check the lens specs before ordering.
• If you don't know your base curve: Get an eye exam. Do not guess. Wearing a lens with the wrong base curve can cause discomfort and potential eye health issues. Schedule an eye exam first.
• If you're between 8.6 and 8.7: Try the 8.6 first, as it's the most common. If you feel the lens is too tight, consult your eye doctor about trying an 8.7. Comfort is your guide; professional advice is best.

FreshTone Lenses and Base Curve

• FreshTone® goddess diva aloe vera colored contacts: Made with high-quality materials that are safe and comfortable to wear. Designed with a breathable structure that keeps your eyes fresh and prevents dryness. A breathable, comfortable lens is essential when you're wearing a standard base curve. This design helps reduce irritation, making it easier to wear for extended periods.
• FreshTone® premium emerald green colored contacts with prescription (myopia): Unique and mesmerizing goddess color with a blend of emerald green that will make your eyes pop. Made with high-quality materials that are safe and comfortable to wear. If you need a prescription, this lens combines vision correction with a comfortable fit. The high-quality material helps maintain comfort, which is especially important if you wear contacts daily.

Fit Guidance

Best For

• People with an average corneal curvature (typically 8.6 mm) who want a wide selection of colored contacts.
• Those who have a valid contact lens prescription and want to order colored lenses online.

Not For

• People with a very flat or steep cornea who need a custom base curve (outside the standard 8.6–8.7 range).

Choosing the right base curve for your colored contacts is essential for comfort and eye health. Always get a professional eye exam, know your measurements, and use a base curve chart to guide your purchase. With the right fit, you can enjoy beautiful, comfortable colored contacts every day.